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Ondansetron 4 mg/5mL Solution — NDC 51672-4091-3 (Billing 51672-4091-03)

by Taro Pharmaceuticals U.S.A., Inc. · 1 BOTTLE in 1 CARTON / 50 mL in 1 BOTTLE

This is a package of Ondansetron 4 mg/5mL Solution from Taro Pharmaceuticals U.S.A., Inc., no longer marketed (first marketed Nov 2007), no longer in the FDA NDC Directory; retail pharmacies pay about $0.2901 per mL (NADAC). It is this product's only package size.

NDC 51672-4091-03
🏷️ FDA NDC (as labeled) 51672-4091-3 billing pads the package segment with a zero
Rx only Generic Discontinued Non-controlled ⚠ Discontinued by firm ⇄ Compare with another NDC
🗂️ FDA directory synced Oct 1, 2026 · this listing last changed Jul 16, 2026 · sources: openFDA · FDA label (DailyMed) · FDA Orange & Purple Book · First Databank · CMS NADAC, ASP, Medicare & Medicaid · RxNorm
📋 All sources & update times →

This page is curated, coded, and maintained by

Compiled from public FDA, CMS, DailyMed, NADAC, and related drug data sources. Editorial policy

NDC database record

One package, one record: these facts belong to NDC 51672-4091-3 alone.

Record
FDA NDC Directory package listing · Human prescription drug
Code segments
51672 labeler · 4091 product · 3 package
Package marketed since
Nov 30, 2007
Sample package
No — commercial package
Listing certified through
Dec 31, 2026
Barcode (UPC)
0351672409135
Medicaid fills, this package
747 prescriptions in the last four reported quarters
FDA record last changed
Jul 16, 2026
⚠️
Excluded from the active FDA NDC Directory. The labeler reported this product as discontinued, so it is excluded from the active NDC Directory. The listing was last certified through Nov 2007. A label may still appear on DailyMed, but the NDC is no longer in the current FDA NDC Directory. Search the FDA NDC Directory ↗

Identity & classification

Regulatory identifiers FDA, NLM and CMS codes for this package

FDA NDC (as labeled) 51672-4091-3
Product NDC 51672-4091
11-digit billing NDC 51672409103
NCPDP billing unit ML — per mL (volume)
RxCUI 312085
UNII NMH84OZK2B
UPC 0351672409135
Application # ANDA077009
SPL Set ID a95ca4f4-c4de-4822-9a08-209d10bf5136
Established class (EPC) Serotonin-3 Receptor Antagonist
Mechanism of action Serotonin 3 Receptor Antagonists
DEA schedule Non-controlled
Marketing category ANDA
Marketing status Discontinued
FDA listing status Discontinued by firm (certified through Nov 2007)
Marketing start 2007-11-30
Route ORAL
Dosage form SOLUTION
Substance ONDANSETRON HYDROCHLORIDE

Drug-database identifiers Medi-Span GPI and First Databank GCN / HICL / AHFS classification

GPI-14 50250065052070
GPI class Ondansetron HCl
GCN Seq No 028107
GCN 20040
HICL code 006055
Ingredient (HICL) Ondansetron Hcl
HIC1 code H
Therapeutic class — broad (HIC1) Nervous System (Except Autonomic)
HIC2 code H6
Therapeutic class — intermediate (HIC2) Drugs Acting Principally On The Midbrain
HIC3 code H6J
Therapeutic class — specific (HIC3) Antiemetic/Antivertigo Agents
AHFS code 56:22.20.00
AHFS class 5-Ht3 Receptor Antagonists
FDB label name ONDANSETRON 4 MG/5 ML SOLUTION
FDB brand name Ondansetron Hcl
Legend status F — Federal legend — prescription drug or device
Quick answers
  • GSN (GCN sequence number): 028107
  • GCN: 20040
  • GPI-14 (Medi-Span): 50250065052070
  • HICL (First Databank): 006055
  • AHFS class code: 56:22.20.00
  • RxCUI (RxNorm): 312085
Why two NDCs? The FDA registers this code as 51672-4091-3 — a 5-4-1 layout, and that's what's printed on the package and shown on DailyMed. For insurance claims, every NDC is standardized to a uniform 11-digit 5-4-2 format by adding a zero to the package segment → 51672-4091-03. Same drug, same package — only the format differs.
Where does this data come from?
Identifiers from the FDA openFDA NDC Directory and Structured Product Labeling; RxCUI from RxNorm (NLM); GPI from Medi-Span; GCN / HIC / AHFS / legend from First Databank.

RxNorm drug class

This medicine belongs to the Serotonin-3 Receptor Antagonist class.

Pharmacologic class Serotonin-3 Receptor Antagonist
Drug family (ATC) Serotonin (5HT3) antagonists
How it works Serotonin 3 Receptor Antagonists
Where does this data come from?
Therapeutic classes from RxNorm RxClass (U.S. National Library of Medicine) — Established Pharmacologic Class (FDA), ATC drug family (WHO) and mechanism of action, matched by this product’s RxCUI.

Clinical

Label name ONDANSETRON 4 MG/5 ML SOLUTION Ingredient Ondansetron Hcl
📗 Our plain-language guide HelloPharmacist
  • Not at all. Ondansetron is approved to prevent nausea and vomiting from cancer chemotherapy, radiation therapy to the abdomen or whole body, and surgery. So you might receive it be...
  • What exactly is ondansetron used for — is it just for chemo patients?
  • The regular tablet is swallowed like any other pill. The orally disintegrating tablet (ODT) is placed on your tongue and allowed to dissolve — don't chew or swallow it whole. For c...
  • How do I take the tablet or the dissolving tablet correctly?
📖 Read our full Ondansetron guide →

Supplement & herbal interactions

🌿 Drug–supplement interaction checker →
Where does this data come from?
Plain-language summary from MedlinePlus (U.S. National Library of Medicine); supplement & herbal interactions and nutrient depletion data from the Natural Medicines database; our full guide is HelloPharmacist editorial content.

Pricing

A drug doesn't have one price. Each row is a different public payment system, and none is what you'd pay at the counter — that depends on your insurance. The ⓘ on each row explains what it measures.

Price systemPer mLPer package
Retail pharmacies payNADAC · weekly $0.290 $14.51 / 50 ml
Medicaid paysCMS SDUD · 12 mo $0.5229 $26.15 / 50 ml
Medicare drug plans payPart D · Q2 2026 $0.4859 $24.30 / 50 ml
Medicare Part B allowsASP · Q0162 $0.016 / Q0162 unit —
NADAC price history (per mL) — tap or hover for the price & month
Dec 2021 Apr 2022 Sep 2022 Feb 2024 $0.290 $0.226
▲ Up 15% over the last 15 months.
Where does this data come from?
NADAC (National Average Drug Acquisition Cost) is the CMS weekly pharmacy-acquisition-cost survey — what pharmacies pay. ASP (Average Sales Price) is the CMS Medicare Part B drug-payment file, published quarterly. Medicaid pays is computed by us from CMS State Drug Utilization Data (total reimbursed ÷ units, trailing 12 months) — gross of rebates and inclusive of dispensing fees, so it reflects what Medicaid paid, not an acquisition cost. Medicare drug plans pay is the median negotiated point-of-sale unit cost across plans listing this NDC in the CMS quarterly Prescription Drug Plan pricing files, before rebates. The VA pays is the federal contract price (FSS, and the statutory Big 4 ceiling where listed) from the VA National Acquisition Center pharmaceutical price file. All are free public government data; each measures a different payer, so the figures are not directly comparable.

Billing & reimbursement

FDA NDC (as labeled)51672-4091-3
11-digit billing NDC51672-4091-03
Format5-4-1 as registered → padded to 5-4-2 for billing (zero added to the package segment)
HCPCS J-codeQ0162
DescriptorONDANSETRON 1 MG, ORAL, FDA APPROVED PRESCRIPTION ANTI-EMETIC, FOR USE AS A COMPLETE THERAPEUTIC SUBSTITUTE FOR AN IV ANTI-EMETIC AT THE TIME OF CHEMOTHERAPY TREATMENT, NOT TO EXCEED A 48 HOUR DOSAGE REGIMEN
Billing units / pkg0.8 units
How the units are derivedThis package is 1 ML; the HCPCS unit is 1 MG, so one package = 0.8 billing units.
Medicare Part B spend (2026 (Q1))$34 · 127 claims · $0.27 per claim (all NDCs under Q0162)
Crosswalk sourcePDAC NDC-HCPCS crosswalk (DME MAC / DMEPOS)
Where does this data come from?
The HCPCS J-code crosswalk comes from the CMS ASP NDC-HCPCS crosswalk and the DMEPDAC (DME MAC) NDC-HCPCS crosswalk — free public CMS data. Billing units are derived from the code’s descriptor and the package amount.

Packaging — all sizes for this product

Package NDCDescription Marketing startMarketing endStatus
51672-4091-03 You're viewing this Main listing 1 BOTTLE in 1 CARTON / 50 mL in 1 BOTTLE 2007-11-30 — Discontinued by firm

Therapeutic equivalents

ProductLabelerPackNADAC/unitTEStatusPrice vs. this
Ondansetron Hydrochloride 4 mg/5mL 00054-0064-47 Hikma 1 bottle $0.286 AA Availability likely save 1%
Ondansetron 4 mg/5mL 00121-0882-51 PAI 50 ml $0.286 AA Availability likely save 1%
Ondansetron 4 mg/5mL 16714-0671-02 NorthStar 1 bottle $0.286 AA Availability likely save 1%
Ondansetron Hydrochloride 4 mg/5mL 62135-0555-58 Chartwell 50 ml $0.286 AA Availability likely save 1%
Ondansetron 4 mg/5mL 65162-0691-79 Amneal 50 ml $0.286 AA Availability likely save 1%
Ondansetron 4 mg/5mLthis 51672-4091-03 Taro 1 bottle $0.290 — Discontinued —
Ondansetron 4 mg/5mL 00121-4882-94 PAI 10 cups — AA FDA listed —
Ondansetron 4 mg/5mL 17856-0672-01 Atlantic 60 syringes — AA FDA listed —
Ondansetron 4 mg/5mL 17856-0691-01 ATLANTIC 1.5 ml — AA FDA listed —
Ondansetron 4 mg/5mL 50268-0647-14 AvPAK 40 cups — AA FDA listed —
Ondansetron 4 mg/5mL 60687-0252-86 American 10 cups — AA FDA listed —
Ondansetron 4 mg/5mL 65862-0208-04 Aurobindo 1 bottle — AA FDA listed —
Ondansetron 4 mg/5mL 68071-3611-05 NuCare 1 bottle — AA FDA listed —
Ondansetron Hydrochloride 4 mg/5mL 68094-0763-62 Precision 10 cups — AA FDA listed —
Ondansetron Hydrochloride 4 mg/5mL 68999-0555-24 Chartwell 10 cups — AA FDA listed —
About this product: this is a generic version of the medicine. FDA equivalence ratings are shown when available, and other versions are listed above, least expensive first.
Where does this data come from?
Equivalents are other NDCs of the same ingredient, form and route from the openFDA NDC Directory, ranked least-expensive-first by NADAC. Therapeutic-equivalence (AB) ratings come from the FDA Orange Book; biologics use the FDA Purple Book for biosimilar & interchangeable status.

Availability & generic status

🏛️
2007
On the market since
Nov 2007
📍
2026
Currently FDA-listed
19 years listed
🔓
·
Generic on the market
this product is a generic
✅This is a generic drug

This product is an FDA-approved generic. Other versions of the same drug are listed under Therapeutic equivalents, least expensive first.

Where does this data come from?
Patents and exclusivity from the FDA Orange Book (small-molecule drugs), refreshed from public FDA data. Generic launch timing is an estimate, not a guarantee.

Inactive Ingredients / Excipients

Inactive ingredients, also called excipients, are components of the drug product other than the active ingredient. They may include fillers, dyes, coatings, preservatives, flavors, or other formulation ingredients.

🧪 Avoiding an ingredient? See Ondansetron inactive ingredients by manufacturer: every current product's list side by side, so you can ask your pharmacy for the version that does not list it.

Loading inactive ingredients from the official FDA label in the background. No external source is being called by this page request.
Where does this data come from?
Source: official FDA Structured Product Labeling (SPL) via DailyMed and the openFDA label index. Structured IACT rows and label-wide narrative are kept separate; availability and product-level specificity depend on the submitted label.

Inactive ingredient FAQ

Are inactive ingredients the same for every manufacturer?
No. Inactive ingredients can differ by manufacturer, dosage form, strength, and package / product version.
Why might an inactive ingredient be missing?
Some SPLs do not provide a complete structured inactive-ingredient list, and older or unusual labels may only include the information in narrative text.
Can inactive ingredients matter?
Yes. They can matter for allergies, intolerances, dyes, gluten / lactose concerns, preservatives, and formulation differences — but confirm with a pharmacist or the manufacturer when it’s clinically important.

Manufacturer & labeler

LabelerTaro Pharmaceuticals U.S.A., Inc.
Application holderTARO PHARMACEUTICAL INDUSTRIES LTD
FDA applicationANDA077009 (ANDA)
Labeler code51672
First marketedNov 2007
Product typeHuman Prescription Drug
Portfolio52 products on file

More NDCs from Taro Pharmaceuticals U.S.A., Inc. labeler code 51672

The labeler markets the product; the application holder owns the FDA approval. They’re often the same company but can differ (e.g. a repackager or an authorized generic). A mailing address / phone appears here when the manufacturer includes it in the product’s FDA label (not all do).
Where does this data come from?
Labeler, application holder and registered establishment from the FDA openFDA NDC Directory and Drugs@FDA; address/contact from the product’s FDA label.

Full prescribing information FDA SPL

The complete FDA label for this product — the official prescribing information, verbatim, section by section. Very long sections are excerpted here and marked; the full text is on DailyMed (linked in the sources below). Jump with a chip, search within the label, or expand everything.
🎯 Indications and Usage ⏱️ Dosage and Administration 💊 Dosage Forms and Strengths ⛔ Contraindications ⚠️ Warnings and Cautions 🤒 Adverse Reactions 🔄 Drug Interactions 👥 Use in Specific Populations 🤰 Pregnancy 🧒 Pediatric Use 🧓 Geriatric Use 🆘 Overdosage 🧬 Clinical Pharmacology 🧬 Mechanism of Action 📦 How Supplied / Storage and Handling 📦 Storage and Handling 📋 Description 💬 Information for Patients 🧬 Pharmacokinetics 🧬 Pharmacodynamics 🔬 Clinical Studies 🔒 Drug Abuse and Dependence 🧪 Nonclinical Toxicology 📄 Carcinogenesis, Mutagenesis, Impairment of Fertility 📄 Package Label / Principal Display Panel
🎯 Indications and Usage 159 words ▾

1 INDICATIONS AND USAGE Ondansetron is indicated for the prevention of nausea and vomiting associated with: highly emetogenic cancer chemotherapy, including cisplatin greater than or equal to 50 mg/m 2 . initial and repeat courses of moderately emetogenic cancer chemotherapy. radiotherapy in patients receiving either total body irradiation, single high-dose fraction to the abdomen, or daily fractions to the abdomen. Ondansetron is also indicated for the prevention of postoperative nausea and/or vomiting. Ondansetron is a 5-HT 3 receptor antagonist indicated for the prevention of: nausea and vomiting associated with highly emetogenic cancer chemotherapy, including cisplatin greater than or equal to 50 mg/m 2 .

( 1 ) nausea and vomiting associated with initial and repeat courses of moderately emetogenic cancer chemotherapy. ( 1 ) nausea and vomiting associated with radiotherapy in patients receiving either total body irradiation, single high-dose fraction to the abdomen, or daily fractions to the abdomen. ( 1 ) postoperative nausea and/or vomiting.

( 1 )

⏱️ Dosage and Administration ~2 min read ▾

2 DOSAGE AND ADMINISTRATION See full prescribing information for the recommended dosage in adults and pediatrics. ( 2 ) Patients with severe hepatic impairment: do not exceed a total daily dose of 8 mg. ( 2.2 , 8.6 )

2.1Dosage The recommended dosage regimens for adult and pediatric patients are described in Table 1 and Table 2, respectively. Corresponding doses of ondansetron tablets and ondansetron oral solution may be used interchangeably. Table 1: Adult Recommended Dosage Regimen for Prevention of Nausea and Vomiting Indication Dosage Regimen Highly Emetogenic Cancer Chemotherapy A single 24-mg dose administered 30 minutes before the start of single-day highly emetogenic chemotherapy, including cisplatin greater than or equal to 50 mg/m 2 Moderately Emetogenic Cancer Chemotherapy 8 mg administered 30 minutes before the start of chemotherapy, with a subsequent 8-mg dose 8 hours after the first dose.

Then administer 8 mg twice a day (every 12 hours) for 1 to 2 days after completion of chemotherapy. Radiotherapy For total body irradiation: 8 mg administered 1 to 2 hours before each fraction of radiotherapy each day. For single high-dose fraction radiotherapy to the abdomen: 8 mg administered 1 to 2 hours before radiotherapy, with subsequent 8-mg doses every 8 hours after the first dose for 1 to 2 days after completion of radiotherapy.

For daily fractionated radiotherapy to the abdomen: 8 mg administered 1 to 2 hours before radiotherapy, with subsequent 8-mg doses every 8 hours after the first dose for each day radiotherapy is given. Postoperative 16 mg administered 1 hour before induction of anesthesia. Table 2: Pediatric Recommended Dosage Regimen for Prevention of Nausea and Vomiting Indication Dosage Regimen Moderately Emetogenic Cancer Chemotherapy 12 to 17 years of age: 8 mg administered 30 minutes before the start of chemotherapy, with a subsequent 8-mg dose 8 hours after the first dose.

Then administer 8 mg twice a day (every 12 hours) for 1 to 2 days after completion of chemotherapy. 4 to 11 years of age: 4 mg administered 30 minutes before the start of chemotherapy, with a subsequent 4-mg dose 4 and 8 hours after the first dose. Then administer 4 mg three times a day for 1 to 2 days after completion of chemotherapy.

2.2Dosage in Hepatic Impairment In patients with severe hepatic impairment (Child-Pugh score of 10 or greater), do not exceed a total daily dose of 8 mg [see Use in Specific Populations (8.6) , Clinical Pharmacology (12.3) ] .

💊 Dosage Forms and Strengths 38 words ▾

3 DOSAGE FORMS AND STRENGTHS Ondansetron oral solution USP, 4 mg/5 mL, is a clear, colorless to light yellow liquid with a characteristic strawberry odor available in a 50-mL bottle. Oral Solution: 4 mg/5 mL ( 3 )

⛔ Contraindications 68 words ▾

4 CONTRAINDICATIONS Ondansetron is contraindicated in patients: known to have hypersensitivity (e.g., anaphylaxis) to ondansetron or any of the components of the formulation [see Adverse Reactions (6.2) ] . receiving concomitant apomorphine due to the risk of profound hypotension and loss of consciousness. Patients known to have hypersensitivity (e.g., anaphylaxis) to ondansetron or any components of the formulation. ( 4 ) Concomitant use of apomorphine.

( 4 )

⚠️ Warnings and Cautions ~2 min read ▾

5 WARNINGS AND PRECAUTIONS Hypersensitivity reactions including anaphylaxis and bronchospasm: Discontinue ondansetron if suspected. Monitor and treat promptly per standard of care until signs and symptoms resolve. ( 5.1 ) QT interval prolongation and Torsade de Pointes : Avoid in patients with congenital long QT syndrome; monitor with electrocardiograms (ECGs) if concomitant electrolyte abnormalities, cardiac failure or arrhythmias, or use of other QT prolonging drugs.

( 5.2 ) Serotonin syndrome: Reported with 5-HT 3 receptor antagonists alone but particularly with concomitant use of serotonergic drugs. If such symptoms occur, discontinue ondansetron and initiate supportive treatment. If concomitant use of ondansetron with other serotonergic drugs is clinically warranted, patients should be made aware of a potential increased risk for serotonin syndrome.

( 5.3 ) Masking of progressive ileus and/or gastric distention following abdominal surgery or chemotherapy-induced nausea and vomiting : Monitor for decreased bowel activity, particularly in patients with risk factors for gastrointestinal obstruction. ( 5.4 )

5.1Hypersensitivity Reactions Hypersensitivity reactions, including anaphylaxis and bronchospasm, have been reported in patients who have exhibited hypersensitivity to other selective 5-HT 3 receptor antagonists. If hypersensitivity reactions occur, discontinue use of ondansetron; treat promptly per standard of care and monitor until signs and symptoms resolve [see Contraindications (4) ].

5.2QT Prolongation Electrocardiogram (ECG) changes including QT interval prolongation have been seen in patients receiving ondansetron. In addition, postmarketing cases of Torsade de Pointes have been reported in patients using ondansetron. Avoid ondansetron in patients with congenital long QT syndrome.

ECG monitoring is recommended in patients with electrolyte abnormalities (e.g., hypokalemia or hypomagnesemia), congestive heart failure, bradyarrhythmias, or patients taking other medicinal products that lead to QT prolongation [see Clinical Pharmacology (12.2) ].

5.3Serotonin Syndrome The development of serotonin syndrome has been reported with 5-HT 3 receptor antagonists alone. Most reports have been associated with concomitant use of serotonergic drugs (e.g., selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), monoamine oxidase inhibitors, mirtazapine, fentanyl, lithium, tramadol, and intravenous methylene blue). Some of the reported cases were fatal.

Serotonin syndrome occurring with overdose of ondansetron alone has also been reported. The majority of reports of serotonin syndrome related to 5-HT 3 receptor antagonist use occurred in a post-anesthesia care unit or an infusion center. Symptoms associated with serotonin syndrome may include the following combination of signs and symptoms: mental status changes (e.g., agitation, hallucinations, delirium, and coma), autonomic instability (e.g., tachycardia, labile blood pressure, dizziness, diaphoresis, flushing, hyperthermia), neuromuscular symptoms (e.g., tremor, rigidity, myoclonus, hyperreflexia, incoordination), seizures, with or without gastrointestinal symptoms (e.g., nausea, vomiting, diarrhea).

Patients should be monitored for the emergence of serotonin syndrome, especially with concomitant use of ondansetron and other serotonergic drugs. If symptoms of serotonin syndrome occur, discontinue ondansetron and initiate supportive treatment. Patients should be informed of the increased risk of serotonin syndrome, especially if ondansetron is used concomitantly with other serotonergic drugs [see Drug Interactions (7.1) , Overdosage (10) ] .

5.4Masking of Progressive Ileus and Gastric Distension The use of ondansetron in patients following abdominal surgery or in patients with chemotherapy-induced nausea and vomiting may mask a progressive ileus and/or gastric distension. Monitor for decreased bowel activity, particularly in… [Excerpted — this section continues on DailyMed.]

🤒 Adverse Reactions ~3 min read ▾

6 ADVERSE REACTIONS The most common adverse reactions in adults for the: prevention of chemotherapy-induced (greater than or equal to 5%) are: headache, malaise/fatigue, constipation, diarrhea. ( 6.1 ) prevention of radiation-induced nausea and vomiting (greater than or equal to 2%) are: headache, constipation, and diarrhea. ( 6.1 ) prevention of postoperative nausea and vomiting (greater than or equal to 9%) are: headache and hypoxia.

( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Taro Pharmaceuticals U.S.A., Inc. at 1-866-923-4914 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch .

6.1Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared with rates in the clinical trials of another drug and may not reflect the rates observed in practice. The following adverse reactions have been reported in clinical trials of patients treated with ondansetron, the active ingredient of ondansetron oral solution. A causal relationship to therapy with ondansetron was unclear in many cases.

Prevention of Chemotherapy-induced Nausea and Vomiting The most common adverse reactions reported in greater than or equal to 4% of 300 adults receiving a single 24-mg dose of ondansetron orally in 2 trials for the prevention of nausea and vomiting associated with highly emetogenic chemotherapy (cisplatin greater than or equal to 50 mg/m 2 ) were: headache (11%) and diarrhea (4%). The most common adverse reactions reported in 4 trials in adults for the prevention of nausea and vomiting associated with moderately emetogenic chemotherapy (primarily cyclophosphamide-based regimens) are shown in Table 3.

Table 3: Most Common Adverse Reactions in Adults Reported in greater than or equal to 5% of patients treated with ondansetron and at a rate that exceeded placebo. for the Prevention of Nausea and Vomiting Associated with Moderately Emetogenic Chemotherapy [Primarily Cyclophosphamide-based Regimens] Adverse Reaction Ondansetron 8 mg Twice Daily (n = 242) Placebo (n = 262) Headache 58 (24%) 34 (13%) Malaise/fatigue 32 (13%) 6 (2%) Constipation 22 (9%) 1 (<1%) Diarrhea 15 (6%) 10 (4%) Less Common Adverse Reactions Central Nervous System: Extrapyramidal reactions (less than 1% of patients).

Hepatic: Aspartate transaminase (AST) and/or alanine transaminase (ALT) values exceeded twice the upper limit of normal in approximately 1% to 2% of 723 patients receiving ondansetron and cyclophosphamide-based chemotherapy in US clinical trials. The increases were transient and did not appear to be related to dose or duration of therapy. On repeat exposure, similar transient elevations in transaminase values occurred in some courses, but symptomatic hepatic disease did not occur.

The role of cancer chemotherapy in these biochemical changes is unclear. Liver failure and death has been reported in cancer patients receiving concurrent medications, including potentially hepatotoxic cytotoxic chemotherapy and antibiotics. The etiology of the liver failure is unclear.

Integumentary: Rash (approximately 1% of patients). Other (less than 2%): Anaphylaxis, bronchospasm, tachycardia, angina, hypokalemia, electrocardiographic alterations, vascular occlusive events, and grand mal seizures. Except for bronchospasm and anaphylaxis, the relationship to ondansetron is unclear.

Prevention of Radiation-Induced Nausea and Vomiting The most common adverse reactions (greater than or equal to 2%) reported in patients receiving ondansetron and concurrent radiotherapy were similar to those reported in patients receiving ondansetron and concurrent chemotherapy and were headache, constipation, and diarrhea. Prevention of Postoperative Nausea and Vomiting The most common adverse reactions reported in adults in trial(s) of prevention of postoperative nausea and vomiting are shown in Table 4. In these trial(s), patients were receiving multiple concomitant perioperat… [Excerpted — this section continues on DailyMed.]

🔄 Drug Interactions ~1 min read ▾

7 DRUG INTERACTIONS

7.1Serotonergic Drugs Serotonin syndrome (including altered mental status, autonomic instability, and neuromuscular symptoms) has been described following the concomitant use of 5-HT 3 receptor antagonists and other serotonergic drugs, including selective serotonin reuptake inhibitors (SSRIs) and serotonin and noradrenaline reuptake inhibitors (SNRIs). Monitor for the emergence of serotonin syndrome. If symptoms occur, discontinue ondansetron and initiate supportive treatment [see Warnings and Precautions (5.3) ] .

7.2Drugs Affecting Cytochrome P-450 Enzymes Ondansetron does not itself appear to induce or inhibit the cytochrome P-450 drug-metabolizing enzyme system of the liver [see Clinical Pharmacology (12.3) ] . Because ondansetron is metabolized by hepatic cytochrome P-450 drug-metabolizing enzymes (CYP3A4, CYP2D6, CYP1A2), inducers or inhibitors of these enzymes may change the clearance and, hence, the half-life of ondansetron. In patients treated with potent inducers of CYP3A4 (i.e., phenytoin, carbamazepine, and rifampin), the clearance of ondansetron was significantly increased and ondansetron blood concentrations were decreased.

However, on the basis of available data, no dosage adjustment for ondansetron is recommended for patients on these drugs [see Clinical Pharmacology (12.3) ] .

7.3Tramadol Although no pharmacokinetic drug interaction between ondansetron and tramadol has been observed, data from 2 small trials indicate that when used together, ondansetron may increase patient-controlled administration of tramadol. Monitor patients to ensure adequate pain control when ondansetron is administered with tramadol.

7.4Chemotherapy Carmustine, etoposide, and cisplatin do not affect the pharmacokinetics of ondansetron. In a crossover trial in 76 pediatric patients, intravenous ondansetron did not increase systemic concentrations of high-dose methotrexate.

7.5Alfentanil and Atracurium Ondansetron does not alter the respiratory depressant effects produced by alfentanil or the degree of neuromuscular blockade produced by atracurium. Interactions with general or local anesthetics have not been studied.

👥 Use in Specific Populations ~3 min read ▾

8 USE IN SPECIFIC POPULATIONS

8.1Pregnancy Risk Summary Available data do not reliably inform the association of ondansetron and adverse fetal outcomes. Published epidemiological studies on the association between ondansetron and fetal outcomes have reported inconsistent findings and have important methodological limitations hindering interpretation [ see Data ]. Reproductive studies in rats and rabbits did not show evidence of harm to the fetus when ondansetron was administered during organogenesis at approximately 6 and 24 times the maximum recommended human oral dose of 24 mg/day, based on body surface area, respectively [ see Data ].

The background risk of major birth defects and miscarriage for the indicated population is unknown. In the US general population, the estimated background risk of major birth defects and miscarriages in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Data Human Data Methodological limitations of the epidemiology studies preclude a reliable evaluation of the potential risk of adverse fetal outcomes with the use of ondansetron in pregnancy.

Two large retrospective cohort studies of ondansetron use in pregnancy have been published. In one study with 1,349 infants born to women who reported the use of ondansetron or received an ondansetron prescription in the first trimester, no increased risk for major congenital malformations was seen in aggregate analysis. In this same study, however, a sub-analysis for specific malformations reported an association between ondansetron exposure and cardiovascular defect (odds ratio (OR) 1.62 [95% CI (1.04, 2.14)]) and cardiac septal defect (OR 2.05 [95% CI (1.19, 3.28)]).

The second study examined 1970 women who received ondansetron prescription during pregnancy and reported no association between ondansetron exposure and major congenital malformations, miscarriage or stillbirth, and infants of low birth weight or small for gestational age. Important methodological limitations with these studies include the uncertainty of whether women who filled a prescription actually took the medication, the concomitant use of other medications or treatments, and other unadjusted confounders that may account for the study findings.

A case-control study evaluating associations between several common non-cardiac malformations and multiple antiemetic drugs reported an association between maternal use of ondansetron and isolated cleft palate (reported adjusted OR = 2.37 [95% CI (1.18, 4.76)]). However, this association could be a chance finding, given the large number of drugs-birth defect comparisons in this study. It is unknown whether ondansetron exposure in utero in the cases of cleft palate occurred during the time of palate formation (the palate is formed between the 6 th and 9 th weeks of pregnancy) or whether mothers of infants with cleft palate used other medications or had other risk factors for cleft palate in the offspring.

In addition, no cases of isolated cleft palate were identified in the aforementioned two large retrospective cohort studies. At this time, there is no clear evidence that ondansetron exposure in early pregnancy can cause cleft palate. Animal Data In embryo-fetal development studies in rats and rabbits, pregnant animals received oral doses of ondansetron up to 15 mg/kg/day and 30 mg/kg/day, respectively, during the period of organogenesis.

With the exception of a slight decrease in maternal body weight gain in the rabbits, there were no significant effects of ondansetron on the maternal animals or the development of the offspring. At doses of 15 mg/kg/day in rats and 30 mg/kg/day in rabbits, the maternal exposure margin was approximately 6 and 24 times the maximum recommended human oral dose of 24 mg/day, respectively, based on body surface area. In a pre- and postnatal developmental toxicity study, pregnant rats received oral doses of ondansetron up to 15 mg/kg/day from Day 17 of pregnancy to litter Day 21.

With the ex… [Excerpted — this section continues on DailyMed.]

🤰 Pregnancy ~3 min read ▾

8.1Pregnancy Risk Summary Available data do not reliably inform the association of ondansetron and adverse fetal outcomes. Published epidemiological studies on the association between ondansetron and fetal outcomes have reported inconsistent findings and have important methodological limitations hindering interpretation [ see Data ]. Reproductive studies in rats and rabbits did not show evidence of harm to the fetus when ondansetron was administered during organogenesis at approximately 6 and 24 times the maximum recommended human oral dose of 24 mg/day, based on body surface area, respectively [ see Data ].

The background risk of major birth defects and miscarriage for the indicated population is unknown. In the US general population, the estimated background risk of major birth defects and miscarriages in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Data Human Data Methodological limitations of the epidemiology studies preclude a reliable evaluation of the potential risk of adverse fetal outcomes with the use of ondansetron in pregnancy.

Two large retrospective cohort studies of ondansetron use in pregnancy have been published. In one study with 1,349 infants born to women who reported the use of ondansetron or received an ondansetron prescription in the first trimester, no increased risk for major congenital malformations was seen in aggregate analysis. In this same study, however, a sub-analysis for specific malformations reported an association between ondansetron exposure and cardiovascular defect (odds ratio (OR) 1.62 [95% CI (1.04, 2.14)]) and cardiac septal defect (OR 2.05 [95% CI (1.19, 3.28)]).

The second study examined 1970 women who received ondansetron prescription during pregnancy and reported no association between ondansetron exposure and major congenital malformations, miscarriage or stillbirth, and infants of low birth weight or small for gestational age. Important methodological limitations with these studies include the uncertainty of whether women who filled a prescription actually took the medication, the concomitant use of other medications or treatments, and other unadjusted confounders that may account for the study findings.

A case-control study evaluating associations between several common non-cardiac malformations and multiple antiemetic drugs reported an association between maternal use of ondansetron and isolated cleft palate (reported adjusted OR = 2.37 [95% CI (1.18, 4.76)]). However, this association could be a chance finding, given the large number of drugs-birth defect comparisons in this study. It is unknown whether ondansetron exposure in utero in the cases of cleft palate occurred during the time of palate formation (the palate is formed between the 6 th and 9 th weeks of pregnancy) or whether mothers of infants with cleft palate used other medications or had other risk factors for cleft palate in the offspring.

In addition, no cases of isolated cleft palate were identified in the aforementioned two large retrospective cohort studies. At this time, there is no clear evidence that ondansetron exposure in early pregnancy can cause cleft palate. Animal Data In embryo-fetal development studies in rats and rabbits, pregnant animals received oral doses of ondansetron up to 15 mg/kg/day and 30 mg/kg/day, respectively, during the period of organogenesis.

With the exception of a slight decrease in maternal body weight gain in the rabbits, there were no significant effects of ondansetron on the maternal animals or the development of the offspring. At doses of 15 mg/kg/day in rats and 30 mg/kg/day in rabbits, the maternal exposure margin was approximately 6 and 24 times the maximum recommended human oral dose of 24 mg/day, respectively, based on body surface area. In a pre- and postnatal developmental toxicity study, pregnant rats received oral doses of ondansetron up to 15 mg/kg/day from Day 17 of pregnancy to litter Day 21.

With the exception of a slight reduction… [Excerpted — this section continues on DailyMed.]

🧒 Pediatric Use 153 words ▾

8.4Pediatric Use The safety and effectiveness of orally administered ondansetron have been established in pediatric patients 4 years and older for the prevention of nausea and vomiting associated with moderately emetogenic cancer chemotherapy. Use of ondansetron in these age-groups is supported by evidence from adequate and well-controlled studies of ondansetron in adults with additional data from 3 open-label, uncontrolled, non-US trials in 182 pediatric patients aged 4 to 18 years with cancer who were given a variety of cisplatin or noncisplatin regimens [see Dosage and Administration (2.2) , Clinical Studies (14.1) ] .

Additional information on the use of ondansetron in pediatric patients may be found in ondansetron injection prescribing information. The safety and effectiveness of orally administered ondansetron have not been established in pediatric patients for: prevention of nausea and vomiting associated with highly emetogenic cancer chemotherapy. prevention of nausea and vomiting associated with radiotherapy. prevention of postoperative nausea and/or vomiting.

🧓 Geriatric Use 148 words ▾

8.5Geriatric Use Of the total number of subjects enrolled in cancer chemotherapy-induced and postoperative nausea and vomiting in U.S.- and foreign-controlled clinical trials, for which there were subgroup analyses, 938 (19%) were aged 65 years and older. No overall differences in safety or effectiveness were observed between subjects 65 years of age and older and younger subjects. A reduction in clearance and increase in elimination half-life were seen in patients older than 75 years compared with younger subjects [see Clinical Pharmacology (12.3) ] .

There were an insufficient number of patients older than 75 years of age and older in the clinical trials to permit safety or efficacy conclusions in this age-group. Other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out. No dosage adjustment is needed in elderly patients.

🆘 Overdosage 172 words ▾

10 OVERDOSAGE There is no specific antidote for ondansetron overdose. Patients should be managed with appropriate supportive therapy. In addition to the adverse reactions listed above, the following adverse reactions have been described in the setting of ondansetron overdose: "Sudden blindness" (amaurosis) of 2 to 3 minutes' duration plus severe constipation occurred in one patient that was administered 72 mg of ondansetron intravenously as a single dose.

Hypotension (and faintness) occurred in a patient that took 48 mg of ondansetron tablets. Following infusion of 32 mg over only a 4-minute period, a vasovagal episode with transient second-degree heart block was observed. In all instances, the adverse reactions resolved completely.

Pediatric cases consistent with serotonin syndrome have been reported after inadvertent oral overdoses of ondansetron (exceeding estimated ingestion of 5 mg per kg) in young children. Reported symptoms included somnolence, agitation, tachycardia, tachypnea, hypertension, flushing, mydriasis, diaphoresis, myoclonic movements, horizontal nystagmus, hyperreflexia, and seizure. Patients required supportive care, including intubation in some cases, with complete recovery without sequelae within 1 to 2 days.

🧬 Clinical Pharmacology ~3 min read ▾

12 CLINICAL PHARMACOLOGY

12.1Mechanism of Action Ondansetron is a selective 5-HT 3 receptor antagonist. While its mechanism of action has not been fully characterized, ondansetron is not a dopamine-receptor antagonist. Serotonin receptors of the 5-HT 3 type are present both peripherally on vagal nerve terminals and centrally in the chemoreceptor trigger zone of the area postrema.

It is not certain whether ondansetron's antiemetic action is mediated centrally, peripherally, or in both sites. However, cytotoxic chemotherapy appears to be associated with release of serotonin from the enterochromaffin cells of the small intestine. In humans, urinary 5-hydroxyindoleacetic acid (5-HIAA) excretion increases after cisplatin administration in parallel with the onset of emesis.

The released serotonin may stimulate the vagal afferents through the 5-HT 3 receptors and initiate the vomiting reflex.

12.2Pharmacodynamics In healthy subjects, single intravenous doses of 0.15 mg/kg of ondansetron had no effect on esophageal motility, gastric motility, lower esophageal sphincter pressure, or small intestinal transit time. Multiday administration of ondansetron has been shown to slow colonic transit in healthy subjects. Ondansetron has no effect on plasma prolactin concentrations.

Cardiac Electrophysiology QTc interval prolongation was studied in a double-blind, single-intravenous dose, placebo- and positive-controlled, crossover trial in 58 healthy subjects. The maximum mean (95% upper confidence bound) difference in QTcF from placebo after baseline correction was 19.5 (21.8) milliseconds and 5.6 (7.4) milliseconds after 15-minute intravenous infusions of 32 mg and 8 mg of ondansetron injection, respectively. A significant exposure-response relationship was identified between ondansetron concentration and ΔΔQTcF.

Using the established exposure-response relationship, 24 mg infused intravenously over 15 minutes had a mean predicted (95% upper prediction interval) ΔΔQTcF of 14.0 (16.3) milliseconds. In contrast, 16 mg infused intravenously over 15 minutes using the same model had a mean predicted (95% upper prediction interval) ΔΔQTcF of 9.1 (11.2) milliseconds. In this study, the 8-mg dose infused over 15 minutes did not prolong the QT interval to any clinically relevant extent.

12.3Pharmacokinetics Absorption Ondansetron is absorbed from the gastrointestinal tract and undergoes some first-pass metabolism. Mean bioavailability in healthy subjects, following administration of a single 8-mg tablet, is approximately 56%. Ondansetron systemic exposure does not increase proportionately to dose.

The area under curve (AUC) from a 16-mg tablet was 24% greater than predicted from an 8-mg tablet dose. This may reflect some reduction of first-pass metabolism at higher oral doses. Food Effects: Bioavailability is also slightly enhanced by the presence of food.

Distribution Plasma protein binding of ondansetron as measured in vitro was 70% to 76% over the concentration range of 10 to 500 ng/mL. Circulating drug also distributes into erythrocytes. Elimination Metabolism and Excretion: Ondansetron is extensively metabolized in humans, with approximately 5% of a radiolabeled dose recovered as the parent compound from the urine.

The metabolites are observed in the urine. The primary metabolic pathway is hydroxylation on the indole ring followed by subsequent glucuronide or sulfate conjugation. In vitro metabolism studies have shown that ondansetron is a substrate for human hepatic cytochrome P-450 enzymes, including CYP1A2, CYP2D6, and CYP3A4.

In terms of overall ondansetron turnover, CYP3A4 played the predominant role. Because of the multiplicity of metabolic enzymes capable of metabolizing ondansetron, it is likely that inhibition or loss of one enzyme (e.g., CYP2D6 genetic deficiency) will be compensated by others and may result in little change in overall rates of ondansetron elimination. Although some nonconjugated metabolites have pharmacologic activity,… [Excerpted — this section continues on DailyMed.]

🧬 Mechanism of Action 125 words ▾

12.1Mechanism of Action Ondansetron is a selective 5-HT 3 receptor antagonist. While its mechanism of action has not been fully characterized, ondansetron is not a dopamine-receptor antagonist. Serotonin receptors of the 5-HT 3 type are present both peripherally on vagal nerve terminals and centrally in the chemoreceptor trigger zone of the area postrema.

It is not certain whether ondansetron's antiemetic action is mediated centrally, peripherally, or in both sites. However, cytotoxic chemotherapy appears to be associated with release of serotonin from the enterochromaffin cells of the small intestine. In humans, urinary 5-hydroxyindoleacetic acid (5-HIAA) excretion increases after cisplatin administration in parallel with the onset of emesis.

The released serotonin may stimulate the vagal afferents through the 5-HT 3 receptors and initiate the vomiting reflex.

📦 How Supplied / Storage and Handling 70 words ▾

16 HOW SUPPLIED/STORAGE AND HANDLING Ondansetron Oral Solution USP, 4 mg/5mL, a clear, colorless to light yellow liquid with a characteristic strawberry odor, contains 5 mg of ondansetron hydrochloride dihydrate equivalent to 4 mg of ondansetron per 5 mL in bottles of 50 mL with child-resistant closures (NDC 51672-4091-3). Store at 20° to 25°C (68° to 77°F) [see USP Controlled Room Temperature]. Protect from light. Store bottles upright in cartons.

📦 Storage and Handling 21 words ▾

Store at 20° to 25°C (68° to 77°F) [see USP Controlled Room Temperature]. Protect from light. Store bottles upright in cartons.

📋 Description 128 words ▾

11 DESCRIPTION The active ingredient in ondansetron oral solution, USP is ondansetron hydrochloride as the dihydrate, the racemic form of ondansetron and a selective blocking agent of the serotonin 5-HT 3 receptor type. Chemically it is (±) 1, 2, 3, 9-tetrahydro-9-methyl-3-[(2-methyl-1H-imidazol-1-yl)methyl]-4H-carbazol-4-one, monohydrochloride, dihydrate. It has the following structural formula: The empirical formula is C 18 H 19 N 3 O∙HCl∙2H 2 O, representing a molecular weight of 365.9.

Ondansetron hydrochloride dihydrate is a white to off-white powder that is soluble in water and normal saline. Each 5 mL of ondansetron oral solution contains 5 mg of ondansetron hydrochloride dihydrate equivalent to 4 mg of ondansetron. Ondansetron oral solution contains the inactive ingredients citric acid anhydrous, purified water, sodium benzoate, sodium citrate dihydrate, strawberry flavor, and sucralose.

Chemical Structure

💬 Information for Patients ~1 min read ▾

17 PATIENT COUNSELING INFORMATION QT Prolongation Inform patients that ondansetron may cause serious cardiac arrhythmias such as QT prolongation. Instruct patients to tell their healthcare provider right away if they perceive a change in their heart rate, if they feel lightheaded, or if they have a syncopal episode. Hypersensitivity Reactions Inform patients that ondansetron may cause hypersensitivity reactions, some as severe as anaphylaxis and bronchospasm.

Instruct patients to immediately report any signs and symptoms of hypersensitivity reactions, including fever, chills, rash, or breathing problems to their healthcare provider. Masking of Progressive Ileus and Gastric Distension Inform patients following abdominal surgery or those with chemotherapy-induced nausea and vomiting that ondansetron may mask signs and symptoms of bowel obstruction. Instruct patients to immediately report any signs or symptoms consistent with a potential bowel obstruction to their healthcare provider.

Drug Interactions Instruct the patient to report the use of all medications, especially apomorphine, to their healthcare provider. Concomitant use of apomorphine and ondansetron may cause a significant drop in blood pressure and loss of consciousness. Advise patients of the possibility of serotonin syndrome with concomitant use of ondansetron and another serotonergic agent such as medications to treat depression and migraines.

Advise patients to seek immediate medical attention if the following symptoms occur: changes in mental status, autonomic instability, neuromuscular symptoms with or without gastrointestinal symptoms.

🧬 Pharmacokinetics ~3 min read ▾

12.3Pharmacokinetics Absorption Ondansetron is absorbed from the gastrointestinal tract and undergoes some first-pass metabolism. Mean bioavailability in healthy subjects, following administration of a single 8-mg tablet, is approximately 56%. Ondansetron systemic exposure does not increase proportionately to dose.

The area under curve (AUC) from a 16-mg tablet was 24% greater than predicted from an 8-mg tablet dose. This may reflect some reduction of first-pass metabolism at higher oral doses. Food Effects: Bioavailability is also slightly enhanced by the presence of food.

Distribution Plasma protein binding of ondansetron as measured in vitro was 70% to 76% over the concentration range of 10 to 500 ng/mL. Circulating drug also distributes into erythrocytes. Elimination Metabolism and Excretion: Ondansetron is extensively metabolized in humans, with approximately 5% of a radiolabeled dose recovered as the parent compound from the urine.

The metabolites are observed in the urine. The primary metabolic pathway is hydroxylation on the indole ring followed by subsequent glucuronide or sulfate conjugation. In vitro metabolism studies have shown that ondansetron is a substrate for human hepatic cytochrome P-450 enzymes, including CYP1A2, CYP2D6, and CYP3A4.

In terms of overall ondansetron turnover, CYP3A4 played the predominant role. Because of the multiplicity of metabolic enzymes capable of metabolizing ondansetron, it is likely that inhibition or loss of one enzyme (e.g., CYP2D6 genetic deficiency) will be compensated by others and may result in little change in overall rates of ondansetron elimination. Although some nonconjugated metabolites have pharmacologic activity, these are not found in plasma at concentrations likely to significantly contribute to the biological activity of ondansetron.

Specific Populations Age: Geriatric Population: A reduction in clearance and increase in elimination half-life are seen in patients older than 75 years compared to younger subjects [see Use in Specific Populations (8.5) ] . Sex: Gender differences were shown in the disposition of ondansetron given as a single dose. The extent and rate of absorption are greater in women than men.

Slower clearance in women, a smaller apparent volume of distribution (adjusted for weight), and higher absolute bioavailability resulted in higher plasma ondansetron concentrations. These higher plasma concentrations may in part be explained by differences in body weight between men and women. It is not known whether these sex-related differences were clinically important.

More detailed pharmacokinetic information is contained in Tables 5 and 6. Table 5: Pharmacokinetics in Male and Female Healthy Subjects after a Single Dose of an Ondansetron 8-mg Tablet Age-group (years) Sex (M/F) Mean Weight (kg) N Peak Plasma Concentration (ng/mL) Time of Peak Plasma Concentration (h) Mean Elimination Half-life (h) Systemic Plasma Clearance L/h/kg Absolute Bioavailability 18 to 40 M 69.0 6 26.2 2.0 3.1 0.403 0.483 F 62.7 5 42.7 1.7 3.5 0.354 0.663 61 to 74 M 77.5 6 24.1 2.1 4.1 0.384 0.585 F 60.2 6 52.4 1.9 4.9 0.255 0.643 ≥75 M 78.0 5 37.0 2.2 4.5 0.277 0.619 F 67.6 6 46.1 2.1 6.2 0.249 0.747 Table 6: Pharmacokinetics in Male and Female Healthy Subjects after a Single Dose of an Ondansetron 24-mg Tablet Age-group (years) Sex (M/F) Mean Weight (kg) N Peak Plasma Concentration (ng/mL) Time of Peak Plasma Concentration (h) Mean Elimination Half-life (h) 18 to 43 M 84.1 8 125.8 1.9

4.7F 71.8 8 194.4 1.6

5.8Renal Impairment: Renal impairment is not expected to significantly influence the total clearance of ondansetron as renal clearance represents only 5% of the overall clearance. However, the mean plasma clearance of ondansetron was reduced by about 50% in patients with severe renal impairment (creatinine clearance less than 30 mL/min). The reduction in clearance was variable and not consistent with an increase in half-life [see Use in Specific Populations (8.7) ] .

Hepatic Im… [Excerpted — this section continues on DailyMed.]

🧬 Pharmacodynamics 193 words ▾

12.2Pharmacodynamics In healthy subjects, single intravenous doses of 0.15 mg/kg of ondansetron had no effect on esophageal motility, gastric motility, lower esophageal sphincter pressure, or small intestinal transit time. Multiday administration of ondansetron has been shown to slow colonic transit in healthy subjects. Ondansetron has no effect on plasma prolactin concentrations.

Cardiac Electrophysiology QTc interval prolongation was studied in a double-blind, single-intravenous dose, placebo- and positive-controlled, crossover trial in 58 healthy subjects. The maximum mean (95% upper confidence bound) difference in QTcF from placebo after baseline correction was 19.5 (21.8) milliseconds and 5.6 (7.4) milliseconds after 15-minute intravenous infusions of 32 mg and 8 mg of ondansetron injection, respectively. A significant exposure-response relationship was identified between ondansetron concentration and ΔΔQTcF.

Using the established exposure-response relationship, 24 mg infused intravenously over 15 minutes had a mean predicted (95% upper prediction interval) ΔΔQTcF of 14.0 (16.3) milliseconds. In contrast, 16 mg infused intravenously over 15 minutes using the same model had a mean predicted (95% upper prediction interval) ΔΔQTcF of 9.1 (11.2) milliseconds. In this study, the 8-mg dose infused over 15 minutes did not prolong the QT interval to any clinically relevant extent.

🔬 Clinical Studies ~3 min read ▾

14 CLINICAL STUDIES

14.1Prevention of Chemotherapy-Induced Nausea and Vomiting Highly Emetogenic Chemotherapy In two randomized, double-blind, monotherapy trials, a single 24-mg oral dose of ondansetron was superior to a relevant historical placebo control in the prevention of nausea and vomiting associated with highly emetogenic cancer chemotherapy, including cisplatin greater than or equal to 50 mg/m 2 . Steroid administration was excluded from these clinical trials. More than 90% of patients receiving a cisplatin dose greater than or equal to 50 mg/m 2 in the historical-placebo comparator experienced vomiting in the absence of antiemetic therapy.

The first trial compared oral doses of ondansetron 24 mg as a single dose, 8 mg every 8 hours for 2 doses, and 32 mg as a single dose in 357 adult cancer patients receiving chemotherapy regimens containing cisplatin greater than or equal to 50 mg/m 2 . The first or single dose was administered 30 minutes prior to chemotherapy. A total of 66% of patients in the ondansetron 24-mg once-a-day group, 55% in the ondansetron 8-mg twice-a-day group, and 55% in the ondansetron 32-mg once-a-day group completed the 24-hour trial period with 0 emetic episodes and no rescue antiemetic medications, the primary endpoint of efficacy.

Each of the 3 treatment groups was shown to be statistically significantly superior to a historical placebo control. In the same trial, 56% of patients receiving a single 24-mg oral dose of ondansetron experienced no nausea during the 24-hour trial period, compared with 36% of patients in the oral ondansetron 8-mg twice-a-day group ( P = 0.001) and 50% in the oral ondansetron 32-mg once-a-day group. Dosage regimens of ondansetron 8 mg twice daily and 32 mg once daily are not recommended for the prevention of nausea and vomiting associated with highly emetogenic chemotherapy [see Dosage and Administration (2.1) ] .

In a second trial, efficacy of a single 24-mg oral dose of ondansetron for the prevention of nausea and vomiting associated with highly emetogenic cancer chemotherapy, including cisplatin greater than or equal to 50 mg/m 2 , was confirmed. Moderately Emetogenic Chemotherapy A randomized, placebo-controlled, double-blind trial was conducted in the US in 67 patients receiving a cyclophosphamide-based chemotherapy regimen containing doxorubicin. The first 8-mg dose of ondansetron was administered 30 minutes before the start of chemotherapy, with a subsequent dose 8 hours after the first dose, followed by 8 mg of ondansetron twice a day for 2 days after the completion of chemotherapy.

Ondansetron was significantly more effective than placebo in preventing vomiting. Treatment response was based on the total number of emetic episodes over the 3-day trial period. The results of this trial are summarized in Table 7: Table 7: Emetic Episodes–Treatment Response in Patients Receiving Moderately Emetogenic Chemotherapy (Cyclophosphamide-based Regimen Containing Doxorubicin) Ondansetron (n = 33) Placebo (n = 34) P Value Treatment response 0 Emetic episodes 20 (61%) 2 (6%) <0.001 1 to 2 Emetic episodes 6 (18%) 8 (24%) More than 2 emetic episodes/withdrawn 7 (21%) 24 (71%) <0.001 Median number of emetic episodes

0.0Undefined Median undefined since at least 50% of the patients were withdrawn or had more than 2 emetic episodes. Median time to first emetic episode (hours) Undefined Median undefined since at least 50% of patients did not have any emetic episodes.

6.5In a double-blind US trial in 336 patients receiving a cyclophosphamide-based chemotherapy regimen containing either methotrexate or doxorubicin, ondansetron 8 mg administered twice a day was as effective as ondansetron 8 mg administered 3 times a day in preventing nausea and vomiting. Ondansetron 8 mg three times daily is not a recommended regimen for the treatment of moderately emetogenic chemotherapy [see Dosage and Administration (2.1) ] . Treatment response was based on the total number of emetic episodes o… [Excerpted — this section continues on DailyMed.]

🔒 Drug Abuse and Dependence 27 words ▾

9 DRUG ABUSE AND DEPENDENCE Animal studies have shown that ondansetron is not discriminated as a benzodiazepine nor does it substitute for benzodiazepines in direct addiction studies.

🧪 Nonclinical Toxicology 109 words ▾

13 NONCLINICAL TOXICOLOGY

13.1Carcinogenesis, Mutagenesis, Impairment of Fertility Carcinogenic effects were not seen in 2-year studies in rats and mice with oral ondansetron doses up to 10 mg/kg per day and 30 mg/kg per day, respectively (approximately 4 and 6 times the maximum recommended human oral dose of 24 mg per day, based on body surface area). Ondansetron was not mutagenic in standard tests for mutagenicity. Oral administration of ondansetron up to 15 mg/kg per day (approximately 6 times the maximum recommended human oral dose of 24 mg per day, based on body surface area) did not affect fertility or general reproductive performance of male and female rats.

📄 Carcinogenesis, Mutagenesis, Impairment of Fertility 106 words ▾

13.1Carcinogenesis, Mutagenesis, Impairment of Fertility Carcinogenic effects were not seen in 2-year studies in rats and mice with oral ondansetron doses up to 10 mg/kg per day and 30 mg/kg per day, respectively (approximately 4 and 6 times the maximum recommended human oral dose of 24 mg per day, based on body surface area). Ondansetron was not mutagenic in standard tests for mutagenicity. Oral administration of ondansetron up to 15 mg/kg per day (approximately 6 times the maximum recommended human oral dose of 24 mg per day, based on body surface area) did not affect fertility or general reproductive performance of male and female rats.

📄 Package Label / Principal Display Panel 32 words ▾

PRINCIPAL DISPLAY PANEL - 50 mL Bottle Carton 50 mL NDC 51672- 4091 -3 Ondansetron Oral Solution USP, 4 mg/5 mL Rx only TARO PRINCIPAL DISPLAY PANEL - 50 mL Bottle Carton

Source: FDA Structured Product Labeling, mirrored from DailyMed / openFDA. Prefer the government’s original formatting? View this label on DailyMed ↗

Medicaid utilization & spend

📍 This exact package only: Medicaid data is reported per full 11-digit NDC — labeler, product and pack size — so every number here is for this package alone, not the drug overall. Other pack sizes report separately.
💊 Pharmacy benefit only: These are Medicaid outpatient pharmacy claims, billed by NDC. They exclude the medical benefit — clinic- or hospital-administered drugs billed under HCPCS J-codes — so drugs used mostly that way (e.g. Avastin, Lucentis, Keytruda) can look low or missing here. That’s expected, not an error.
📅 Q1 2025 – Q1 2026 · 5 quarters of data
ⓘ The newest quarter is usually incomplete when first published; states restate recent quarters in later CMS releases, so the latest figures typically revise upward. State coverage-policy changes can also shift quarter-to-quarter totals.
Prescriptions last 4 qtrs
747
Units reimbursed last 4 qtrs
30.2K
Gross reimbursed last 4 qtrs
$15.8K
Avg / prescription
$21.12
Avg / unit
$0.5229
Latest quarter Q1 2026
221Rx
Medicaid pays / mL
$0.5229
gross reimbursed
vs
NADAC / mL
$0.2901
acquisition cost
=
Spread
+$0.2328
+80% vs cost
What Medicaid paid per mL (before rebates; includes the pharmacy’s dispensing fee) compared with NADAC — the average price pharmacies pay to buy the drug. A positive spread means Medicaid reimbursed more than the purchase price, before manufacturer rebates.
Fee-for-service vs managed care ⓘ
90% FFS
Fee-for-service · 673 Rx Managed care · 74 Rx
State Medicaid map
Alaska: no data reported AK Maine: no data reported ME Washington: no data reported WA Idaho: no data reported ID Montana: no data reported MT North Dakota: no data reported ND Minnesota: no data reported MN Wisconsin: no data reported WI Michigan: no data reported MI New York: 27,319 units · 140 per 100k residents NY Vermont: no data reported VT New Hampshire: no data reported NH Oregon: no data reported OR Nevada: no data reported NV Wyoming: no data reported WY South Dakota: no data reported SD Iowa: no data reported IA Illinois: no data reported IL Indiana: no data reported IN Ohio: no data reported OH Pennsylvania: no data reported PA New Jersey: no data reported NJ Massachusetts: no data reported MA California: no data reported CA Utah: no data reported UT Colorado: no data reported CO Nebraska: no data reported NE Missouri: no data reported MO Kentucky: no data reported KY West Virginia: no data reported WV Virginia: no data reported VA Maryland: no data reported MD Connecticut: no data reported CT Rhode Island: no data reported RI Arizona: no data reported AZ New Mexico: no data reported NM Kansas: no data reported KS Arkansas: no data reported AR Tennessee: no data reported TN North Carolina: no data reported NC South Carolina: no data reported SC Delaware: no data reported DE Oklahoma: no data reported OK Louisiana: no data reported LA Mississippi: no data reported MS Alabama: no data reported AL Georgia: 2,848 units · 25.8 per 100k residents GA D.C.: no data reported DC Hawaii: no data reported HI Texas: no data reported TX Florida: no data reported FL
Units reimbursed · per 100k residents
25.8140
gray = no data reported ⓘ
Colors are per 100,000 residents, so big states don’t automatically dominate. Tap or hover a state for its actual totals.
Tap or hover a state
…for its Medicaid breakdown
🏆 Top states by units · per 100k residents
1 New York 140 /100k
2 Georgia 25.8 /100k
National units — by quarter
💵 About the dollar figures: “reimbursed” is what Medicaid paid pharmacies before confidential manufacturer rebates, so the program’s real net cost is lower than these numbers. Fee-for-service and managed-care claims are combined unless split above. Source: CMS State Drug Utilization Data; per-100k rates use 2023 Census population estimates.

Reported adverse events (FAERS)

Read carefully: FAERS reports are voluntary and unverified. Counts are not incidence, do not establish causation, are subject to reporting bias, and cannot be used to compare one drug to another. Shown for signal context only. Reports for ONDANSETRON (this brand).

Top reported reactions

Nausea14,461
Fatigue10,277
Diarrhoea9,492
Vomiting8,778
Dyspnoea5,970
Headache5,638
Death5,623

Reporter sex

121,843 reports
Male · 38%
Female · 61%
Unknown · 0%

Serious outcomes

Death15,160
Reports over time (by year) — tap or hover for the count & year
2019 2021 2023 2026 12,241 6,221
Most recent year is provisional (FAERS lags ~3 months).
Where does this data come from?
Adverse-event reports from the FDA Adverse Event Reporting System (FAERS) via openFDA. FAERS reports are voluntary and unverified — counts are not incidence and don’t establish causation.

About this NDC listing & data coverage

Finished prescription product No longer marketed (per FDA listing data)
What data is (and isn’t) available for this NDC — tap to expand
NDC identity (package / product / labeler codes) ✓ Available
Labeler ✓ Available
Product & package description ✓ Available
Marketing category & status ✓ Available
Active ingredient / dosage form / route ✓ Available
FDA label (SPL via DailyMed) ✓ Available
Package photos — Not published for this NDC No photo available yet for this listing.
Inactive ingredients (structured) — Not published for this NDC The labeler did not submit a structured excipient list, or no SPL is available.
NADAC pharmacy acquisition price (CMS) ✓ Available
Orange Book / therapeutic-equivalence data — Not published for this NDC Applies only to products approved under an NDA/ANDA; many listings are out of scope.
HCPCS J-code billing crosswalk ✓ Available
Medicaid utilization (CMS SDUD) ✓ Available
“Not published” reflects what the public FDA / CMS / NLM sources provide for this exact package code — it is a property of the data feeds, not a judgment about the product.

Questions about this listing

What does the discontinued status mean for this NDC?
The labeler reported a marketing end date (or the listing was delisted), so this specific package is no longer actively marketed. Remaining stock may still be dispensed for a time, and the NDC stays valid for historical records and claims — but data feeds (pricing, labeling) typically stop updating for it. Other package sizes or other manufacturers' versions of the same medication may still be marketed — see the equivalents section where available.
Is the NDC printed on the package the same as the 11-digit billing NDC?
Yes, they identify this exact package in different formats. The form printed on the packaging and shown on DailyMed is the one the FDA registered. Insurance claims use a fixed 11-digit 5-4-2 format, so the short segment is padded with a leading zero and the dashes are dropped. The Identity section at the top of this page lists each form of this code.
Who lists this product with the FDA?
Taro Pharmaceuticals U.S.A., Inc. is the labeler of record for this NDC — the company under whose FDA-assigned code the package is listed. The labeler may be the manufacturer itself or a distributor marketing the product under its own code.
Do I need a prescription for this product?
This NDC is listed with FDA as a prescription product, so it is dispensed under a prescriber's order. Your pharmacist can tell you whether any over-the-counter forms of the same medication exist.
Does this product have a billing J-code?
Yes — this NDC cross-references HCPCS code Q0162 for medical-claim billing (typically used when a product is administered in a clinical setting rather than dispensed at a retail pharmacy). See the Billing section on this page.
This page identifies an FDA-listed package (the NDC) and reports public regulatory and pricing data about the listing. It is reference information, not a medical recommendation — talk to your pharmacist or prescriber about your own medication.
Where does this data come from?
Listing facts (marketing category, packager status, marketing dates) from the FDA openFDA NDC Directory; label availability from DailyMed; pricing coverage from CMS NADAC; equivalence scope from the FDA Orange Book.
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For educational and professional reference only — not medical advice. Pricing reflects published NADAC and CMS ASP (free public data) and may differ from your acquisition cost; always verify before billing or dispensing.