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ONDANSETRON 8 mg Tablet, Film Coated, 30-count — NDC 63304-0459-30 package photo

ONDANSETRON 8 mg Tablet, Film Coated, 30-count

by Sun Pharmaceutical Industries, Inc. · 30 TABLET, FILM COATED in 1 BOTTLE (63304-459-30)
NDC 63304-0459-30
🏷️ FDA NDC (as labeled) 63304-459-30 billing pads the product segment with a zero
Rx only Generic On market Non-controlled
🗂️ Data synced Jul 24, 2026 · sources: openFDA · FDA label (DailyMed) · FDA Orange & Purple Book · First Databank · CMS NADAC, ASP, Medicare & Medicaid · RxNorm
📋 All sources & update times →
⚠️
Other active recalls for Ondansetron (different manufacturers) — 1 · tap to view
These affect other manufacturers’ products for the same ingredient — not necessarily the exact NDC on this page.
Class II · Dec 30, 2025 — Defective container: Preferred Pharmaceuticals received a letter from the manufacturer Glenmark, that the blister packs are not fully sealed and tablets falling out. Preferred Pharmaceuticals purchased the finished product and repackaged the product for sale. (Glenmark Pharmaceuticals Inc., USA) · FDA recall D-0246-2026
Each entry is an official FDA enforcement report — look up any recall number in the FDA recall database ↗

🆔 Identity & classification

FDA NDC (as labeled) 63304-459-30
Product NDC 63304-459
11-digit billing NDC 63304045930
NCPDP billing unit EA — each (per item)
RxCUI 198052, 312086
UNII NMH84OZK2B
UPC 0363304458305, 0363304459302
Application # ANDA077851
SPL Set ID 834bc56a-657d-4733-9a60-47040cb5c7bf
Established class (EPC) Serotonin-3 Receptor Antagonist
Mechanism of action Serotonin 3 Receptor Antagonists
DEA schedule Non-controlled
Marketing category ANDA
Marketing status On market
FDA listing status Listed (active directory)
Marketing start 2007-06-25
Route ORAL
Dosage form TABLET, FILM COATED
Substance ONDANSETRON HYDROCHLORIDE
GPI-14 50250065050320
GPI class Ondansetron HCl
GCN Seq No 016393
GCN 20042
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 HCL 8 MG TABLET
FDB brand name Ondansetron Hcl
Legend status F — Federal legend — prescription drug or device
TE code (Orange Book) AB · RLD · RS
Why two NDCs? The FDA registers this code as 63304-459-30 — a 5-3-2 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 product segment → 63304-0459-30. 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.

🏭 Manufacturer & labeler

LabelerSun Pharmaceutical Industries, Inc.
Application holderNATCO PHARMA LTD
FDA applicationANDA077851 (ANDA)
Labeler code63304
First marketedJun 2007
Product typeHuman Prescription Drug
Portfolio889 products on file
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.

🩺 Clinical

Label name ONDANSETRON HCL 8 MG TABLET Ingredient Ondansetron Hcl
📖 What it is MedlinePlus · NLM

Ondansetron is used to prevent nausea and vomiting caused by cancer chemotherapy, radiation therapy, and surgery. Ondansetron is in a class of medications called serotonin 5-HT3 receptor antagonists. It works by blocking the action of serotonin, a natural substance that may cause nausea and vomiting.

Read the full MedlinePlus article ↗
📗 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 →
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.

💊 What it looks like

Color White / Yellow
ShapeOval
Imprint8;NO
Size12 mm
ScoringNot scored
One label can cover several strengths, so colors may be combined — always confirm a loose pill against the dispensed prescription label or a pharmacist.
Where does this data come from?
Physical description (imprint, shape, color, scoring, coating) from this product’s FDA Structured Product Labeling (SPL), mirrored from DailyMed / openFDA.

🧪 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.

💡 Tap an ingredient (hover on desktop) to see what it is and why it’s used.

  • UNII M28OL1HH48
    Croscarmellose sodium is a plant-based substance derived from cellulose. It acts as a disintegrant, helping tablets and capsules break down quickly in the digestive system so the medicine can be absorbed.
  • UNII EX438O2MRT
    Ferric oxide yellow is a naturally occurring iron compound used as a colorant in medications. It gives tablets, capsules, and other forms a yellow or golden hue for identification and appearance.
  • UNII 3NXW29V3WO
    Hypromellose is a plant-based thickener made from cellulose. It's used in medicines as a binder to hold ingredients together, a coating for tablets, and a thickener for liquids.
  • UNII EWQ57Q8I5X
    Lactose monohydrate is a natural sugar derived from milk. It serves as a filler and binder in tablets and capsules, helping create the proper size, texture, and consistency of the medicine.
  • UNII 70097M6I30
    Magnesium stearate is a salt made from magnesium and stearic acid, a fatty substance. It's used in tablets and capsules as a lubricant and glidant to help ingredients flow smoothly during manufacturing and prevent sticking.
  • UNII OP1R32D61U
    Microcrystalline cellulose is a purified form of cellulose, a natural fiber from plant sources. It acts as a binder and filler in tablets and capsules, helping hold ingredients together and give the medicine its shape and size.
  • UNII O8232NY3SJ
    A plant-based carbohydrate derived from corn kernels. It acts as a filler to add bulk, a binder to hold ingredients together, and a disintegrant to help the tablet break apart in your stomach for absorption.
  • UNII 15FIX9V2JP
    Titanium dioxide is a bright white mineral powder commonly used as a colorant and opacifying agent. It makes pills and tablets white or lighter in color and helps make coatings non-transparent.
  • UNII XHX3C3X673
    Triacetin is a clear, oily liquid made from glycerin and acetic acid. It works as a plasticizer and solvent in medicines, helping soften coatings and improve how liquids mix together in formulations.

9 inactive ingredients listed in the exact product block matched to this NDC.

Where does this data come from?
Data sourced from official FDA Structured Product Labeling (SPL) via DailyMedingredient classCode="IACT" elements from the exact product block matched by this NDC. Label-section narrative from DailyMed / the openFDA label index is shown separately when available.

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.

💲 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 eaPer package
Retail pharmacies payNADAC · weekly $0.099 $2.98 / 30 tablets
Medicaid paysCMS SDUD · 12 mo $0.4284 $12.85 / 30 tablets
Medicare drug plans payPart D · Q2 2026 $0.1854 $5.56 / 30 tablets
Medicare Part B allowsASP · Q0162 $0.016 / Q0162 unit
NADAC price history (per ea) — tap or hover for the price & month
Dec 2021 Apr 2022 Sep 2022 Feb 2024 $0.109 $0.095
Flat 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)63304-459-30
11-digit billing NDC63304-0459-30
Format5-3-2 as registered → padded to 5-4-2 for billing (zero added to the product 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 / pkg8 units
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.

🔁 Therapeutic equivalents

ProductLabelerPackNADAC/unitTEStatusPrice vs. this
ondansetron 8 mg 00904-6552-61 Major 1 tablet $0.081 AB Availability likely save 18%
Ondansetron 8 mg 16714-0160-01 NorthStar 30 tablets $0.081 AB Availability likely save 18%
Ondansetron Hydrochloride 8 mg 50268-0622-15 AvPAK 1 tablet $0.081 AB Availability likely save 18%
Ondansetron Hydrochloride 8 mg 57237-0076-30 Rising 30 tablets $0.081 AB Availability likely save 18%
Ondansetron 8 mg 62135-0351-05 Chartwell 500 tablets $0.081 Availability likely save 18%
Ondansetron Hydrochloride 8 mg 65862-0188-03 Aurobindo 3 tablets $0.081 Availability likely save 18%
Ondansetron Hydrochloride 8 mg 68084-0221-01 American 1 tablet $0.081 AB Availability likely save 18%
Ondansetron 8 mg 68462-0106-30 Glenmark 30 tablets $0.081 AB Availability likely save 18%
Ondansetron 8 mg 69339-0172-03 Natco 30 tablets $0.081 AB Availability likely save 18%
ondansetron hydrochloride 8 mg 62756-0131-01 Sun 30 tablets $0.092 FDA listed save 7%
Ondansetron 8 mgthis 63304-0459-30 Sun 30 tablets $0.099 AB FDA listed
Ondansetron Hydrochloride 8 mg 42708-0059-05 QPharma, 5 tablets AB FDA listed
Ondansetron Hydrochloride 8 mg 42708-0179-05 QPharma, 5 tablets AB FDA listed
Ondansetron 8 mg 43063-0770-06 PD-Rx 6 tablets AB FDA listed
Ondansetron Hydrochloride 8 mg 43063-0792-06 PD-Rx 6 tablets AB FDA listed
Ondansetron Hydrochloride 8 mg 50090-3185-00 A-S 4 tablets AB FDA listed
Ondansetron Hydrochloride 8 mg 50090-4671-00 A-S 4 tablets AB FDA listed
Ondansetron 8 mg 51407-0004-05 Golden 500 tablets AB FDA listed
Ondansetron Hydrochloride 8 mg 51655-0016-27 Northwind 12 tablets AB FDA listed
Ondansetron Hydrochloride 8 mg 51655-0813-54 Northwind 15 tablets AB FDA listed
Ondansetron Hydrochloride 8 mg 54348-0821-00 Pharmpak, 1 tablet AB FDA listed
Ondansetron 8 mg 55111-0154-01 Dr. 100 tablets AB FDA listed
ondansetron 8 mg 55154-7879-00 Cardinal 1 tablet AB FDA listed
Ondansetron Hydrochloride 8 mg 55700-0627-10 Quality 10 tablets AB FDA listed
Ondansetron Hydrochloride 8 mg 60760-0658-10 St. 10 tablets AB FDA listed
Ondansetron 8 mg 63187-0065-10 Proficient 10 tablets AB FDA listed
ondansetron 8 mg 63187-0513-10 Proficient 10 tablets AB FDA listed
Ondansetron Hydrochloride 8 mg 63187-0709-06 Proficient 6 tablets AB FDA listed
Ondansetron 8 mg 63850-0004-01 Natco 30 tablets AB FDA listed
Ondansetron Hydrochloride 8 mg 67046-1242-03 Coupler 30 tablets AB FDA listed
Ondansetron Hydrochloride 8 mg 68071-1742-03 NuCare 30 tablets AB FDA listed
Ondansetron 8 mg 68071-3713-03 NuCare 30 tablets AB FDA listed
Ondansetron 8 mg 68071-3801-01 NuCare 10 tablets AB FDA listed
Ondansetron Hydrochloride 8 mg 68071-4328-01 NuCare 10 tablets AB FDA listed
Ondansetron Hydrochloride 8 mg 68071-4705-04 NuCare 4 tablets AB FDA listed
Ondansetron Hydrochloride 8 mg 68071-4966-04 NUCARE 4 tablets AB FDA listed
Ondansetron Hydrochloride 8 mg 68788-8582-01 Preferred 10 tablets AB FDA listed
Ondansetron Hydrochloride 8 mg 68788-9402-01 Preferred 10 tablets AB FDA listed
Ondansetron Hydrochloride 8 mg 70518-3511-00 REMEDYREPACK 30 tablets AB FDA listed
Ondansetron 8 mg 70518-4245-00 REMEDYREPACK 30 tablets AB FDA listed
Ondansetron Hydrochloride 8 mg 71205-0744-10 Proficient 10 tablets AB FDA listed
ondansetron 8 mg 71335-0815-00 Bryant 5 tablets AB FDA listed
Ondansetron Hydrochloride 8 mg 71335-1357-00 Bryant 5 tablets AB FDA listed
Ondansetron Hydrochloride 8 mg 71610-0119-88 Aphena 900 tablets AB FDA listed
Ondansetron Hydrochloride 8 mg 72162-2365-05 Bryant 500 tablets AB FDA listed
Ondansetron Hydrochloride 8 mg 76420-0916-00 Asclemed 1000 tablets AB FDA listed
Ondansetron HCL 8 mg 80425-0074-01 Advanced 10 tablets AB FDA listed
Ondansetron HCL 8 mg 80425-0075-01 Advanced 10 tablets AB FDA listed
Ondansetron Hydrochloride 8 mg 85509-1076-01 PHOENIX 10 tablets AB FDA listed
Ondansetron Hydrochloride 8 mg 85766-0053-05 Sportpharm 5 tablets AB 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
Jun 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.

🗺️ 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 63304-0459-30, 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 – Q4 2025 · 4 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
359
Units reimbursed last 4 qtrs
10.3K
Gross reimbursed last 4 qtrs
$4.4K
Avg / prescription
$12.31
Avg / unit
$0.4284
Latest quarter Q4 2025
92Rx
Medicaid pays / ea
$0.4284
gross reimbursed
vs
NADAC / ea
$0.0994
acquisition cost
=
Spread
+$0.3290
+331% vs cost
What Medicaid paid per ea (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
81% FFS 19% MCO
Fee-for-service · 290 Rx Managed care · 69 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: 8,089 units · 41.3 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: 230 units · 2.6 per 100k residents 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: 1,995 units · 18.1 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
2.641.3
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 41.3 /100k
2 Georgia 18.1 /100k
3 Virginia 2.6 /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.

📊 Medicare Part D spend CMS · PART D · 2026 (Q1)

Medicare Part D (outpatient prescription) spending for Ondansetron ODT (matched by generic name) — the program that covers self-administered drugs. 10 manufacturers.
⚠️ Drug-level data: CMS publishes Part D spending by drug, not by NDC — these figures combine every manufacturer, strength and package size sold under the name Ondansetron ODT. That’s a different level of aggregation than the Medicaid card above, which is specific to this exact 11-digit NDC (pack size included), so the two aren’t directly comparable.
Period
Total Part D spend
$27.68M
Claims incl. refills
1.5M
Beneficiaries
1.2M
Spend / beneficiary
$23.24
Spend / claim
$18.06
Trend by period
💵 About the dollar figures: spending is what Part D plans paid before confidential manufacturer rebates, so the program’s real net cost is lower. A blank patient count means fewer than 11 people — CMS hides counts that small to protect privacy. Source: CMS Medicare Quarterly Part D Spending by Drug (data.cms.gov), updated quarterly.

🔬 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 — the ingredient across all brands.

Top reported reactions

Nausea14,459
Fatigue10,275
Diarrhoea9,488
Vomiting8,777
Dyspnoea5,971
Headache5,638
Death5,623

Reporter sex

121,840 reports

Serious outcomes

Death15,162
Disabling2,793
Reports over time (by year) — tap or hover for the count & year
2019 2021 2023 2026 11,463 0
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.

📦 Packaging — all sizes for this product

Package NDCDescription Marketing startStatus
63304-0459-30 You're viewing this 30 TABLET, FILM COATED in 1 BOTTLE (63304-459-30) 2007-06-25 Active

📄 Full prescribing information FDA SPL

The complete FDA label for this product — the official prescribing information, verbatim, section by section. Jump with a chip, search within the label, or expand everything.
🎯 Indications and Usage 160 words

1 INDICATIONS AND USAGE Ondansetron tablets are 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 tablets are also indicated for the prevention of postoperative nausea and/or vomiting.

Ondansetron tablets are a 5-HT3 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. 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 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 60 words

3 DOSAGE FORMS AND STRENGTHS Ondansetron Tablets USP, are available in the following strengths: • 4 mg – white, oval, film-coated tablets engraved with “4” on one side and “NO” on other side. • 8 mg – yellow, oval, film-coated tablets engraved with “8” on one side and “NO” on the other side. Tablets: 4 mg and 8 mg (3)

Contraindications 69 words

4 CONTRAINDICATIONS Ondansetron tablets are 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 tablets 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-HT3 receptor antagonists alone but particularly with concomitant use of serotonergic drugs. If such symptoms occur, discontinue ondansetron tablets and initiate supportive treatment. If concomitant use of ondansetron tablets 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-HT3 receptor antagonists. If hypersensitivity reactions occur, discontinue use of ondansetron tablets; 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 tablets. Avoid ondansetron tablets 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-HT3 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 tablets alone has also been reported. The majority of reports of serotonin syndrome related to 5-HT3 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 tablets and other serotonergic drugs. If symptoms of serotonin syndrome occur, discontinue ondansetron tablets and initiate supportive treatment. Patients should be informed of the increased risk of serotonin syndrome, especially if ondansetron tablets 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 tablets in patients following abdominal surgery or in patients with chemotherapy-induced nausea and vomiting may mask a progressive ileus…

🤒 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 Sun Pharmaceutical Industries, Inc. at 1-800-406-7984 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 tablets. A causal relationship to therapy with ondansetron tablets 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 tablets orally in 2 trials for the prevention of nausea and vomiting associated with highly emetogenic chemotherapy (cisplatin greater than or equal to 50 mg/m2) 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 a for the Prevention of Nausea and Vomiting Associated with Moderately Emetogenic Chemotherapy [Primarily Cyclophosphamide-based Regimens] Adverse Reaction Ondansetron Tablets 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%) a Reported in greater than or equal to 5% of patients treated with ondansetron tablets and at a rate that exceeded placebo. 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 tablets 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 tablets 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 tablets and concurrent radiotherapy were similar to those reported in patients receiving ondansetron tablets 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 t…

🔄 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 tablets 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 tablets 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 tablets 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 tablets do 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 tablets 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 6th and 9th 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 2 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…

🤰 Pregnancy ~3 min read

8.1Pregnancy Risk Summary Available data do not reliably inform the association of ondansetron tablets 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 6th and 9th 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 2 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…

🧒 Pediatric Use 160 words

8.4Pediatric Use The safety and effectiveness of orally administered ondansetron tablets 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 tablets in these age-groups is supported by evidence from adequate and well-controlled studies of ondansetron tablets 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 tablets 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 147 words

8.5Geriatric Use Of the total number of subjects enrolled in cancer chemotherapy-induced and postoperative nausea and vomiting in US-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-HT3 receptor antagonist. While its mechanism of action has not been fully characterized, ondansetron is not a dopamine-receptor antagonist. Serotonin receptors of the 5-HT3 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-HT3 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 15minute 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, the…

🧬 Mechanism of Action 122 words

12.1Mechanism of Action Ondansetron is a selective 5-HT3 receptor antagonist. While its mechanism of action has not been fully characterized, ondansetron is not a dopamine-receptor antagonist. Serotonin receptors of the 5-HT3 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-HT3 receptors and initiate the vomiting reflex.

📦 How Supplied / Storage and Handling 101 words

16 HOW SUPPLIED/STORAGE AND HANDLING Ondansetron Tablets Ondansetron Tablets USP, 4 mg (ondansetron hydrochloride dihydrate equivalent to 4 mg of ondansetron), are white, oval, film-coated tablets engraved with “4” on one side and “NO” on another side. They are supplied as follows: NDC 63304-458-30 Bottles of 30 Ondansetron Tablets USP, 8 mg (ondansetron hydrochloride dihydrate equivalent to 8 mg of ondansetron), are yellow, oval, film-coated tablets engraved with “8” on one side and “NO” on the other side. They are supplied as follows: NDC 63304-459-30 Bottles of 30 Store at 20° to 25°C (68° to 77°F). [See USP Controlled Room Temperature].

📋 Description 149 words

11 DESCRIPTION The active ingredient in ondansetron tablets is ondansetron hydrochloride as the dihydrate, the racemic form of ondansetron and a selective blocking agent of the serotonin 5-HT3 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 C18H19N3O•HCl•2H2O, representing a molecular weight of 365.5.

Ondansetron hydrochloride dihydrate is a white to off-white powder that is soluble in water and normal saline. Each 4 mg ondansetron tablet, USP for oral administration contains ondansetron hydrochloride dihydrate equivalent to 4 mg of ondansetron. Each 8 mg ondansetron tablet, USP for oral administration contains ondansetron hydrochloride dihydrate equivalent to 8 mg of ondansetron.

Each tablet also contains the inactive ingredients croscarmellose sodium, hypromellose, lactose monohydrate, magnesium stearate, microcrystalline cellulose, pregelatinized starch, titanium dioxide, triacetin, and iron oxide yellow (8 mg tablet only). This product meets USP Dissolution Test 3. Structure

💬 Information for Patients ~1 min read

17 PATIENT COUNSELING INFORMATION QT Prolongation Inform patients that ondansetron tablets 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 tablets 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 tablets 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 tablets 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 tablets 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.

Distributed by: Sun Pharmaceutical Industries, Inc. Cranbury, NJ 08512 USA Manufactured by: Natco Pharma Limited Kothur- 509 228, India Revised: 01/2019 346169

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