Dolasetron
Dolasetron is a serotonin blocker used to prevent nausea and vomiting caused by cancer chemotherapy.
🧬 Where this information comes from Click to expand
The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 1 clinical label set within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →
Dolasetron (Anzemet) is a tablet that prevents chemotherapy nausea and vomiting in adults and children 2 and older by blocking serotonin (5-HT3) receptors in the gut and the brain's vomiting center; it is a less often prescribed cousin of ondansetron, on the U.S. market since about 2009. Most people tolerate it well, and headache, tiredness or diarrhea are the side effects they tend to notice. The one thing to watch is its effect on heart rhythm, so get help right away for a racing or irregular heartbeat or fainting. Older adults and people with heart or kidney problems carry the most risk and may need an ECG (heart tracing).
Clinical pearls
- Take it about an hour before chemotherapy; food does not affect absorption, so a meal is fine.
- Antidepressants, tramadol, lithium and fentanyl can combine with it to cause serotonin syndrome (agitation, fever, muscle stiffness).
- Low potassium or magnesium must be corrected first, so mention water pills or recent vomiting that can drain them.
- Cimetidine (a heartburn drug) raises dolasetron's active form and rifampin lowers it, so mention either one.
Patient information guide A plain-language walkthrough of Dolasetron, written from its FDA label.
What Dolasetron is used for
▾
Dolasetron is used to prevent nausea and vomiting triggered by cancer chemotherapy.
- Anzemet Tablets are approved to prevent nausea and vomiting caused by moderately emetogenic (nausea-inducing) cancer chemotherapy in adults and in children 2 years of age and older, including both first-time and repeat treatment courses.
How Dolasetron works
▾
Dolasetron works by blocking serotonin receptors known as 5-HT3 receptors. When chemotherapy is given, it triggers the release of serotonin (a chemical messenger) in the small intestine. That serotonin activates 5-HT3 receptors on nerve pathways that send signals to the brain's vomiting center. By blocking those receptors — both in the gut and in the brain — dolasetron interrupts that chain reaction and prevents the nausea and vomiting reflex from firing.
Unlike some older anti-nausea drugs, dolasetron has very little activity at dopamine receptors and does not appear to affect mood, concentration, or colonic (large intestine) movement in humans.
Dolasetron dosage
▾
Anzemet Tablets are taken by mouth roughly one hour before chemotherapy. Food does not affect how well the drug is absorbed, so you can take it with or without a meal. No dosage adjustment is needed for liver or kidney disease, but your doctor may want to monitor your heart rhythm (ECG) if you have kidney impairment or are older.
- Take Anzemet Tablets approximately one hour before chemotherapy starts
- Can be taken with or without food
- Do not exceed the dose your prescriber has prescribed
- Always follow your prescriber's specific instructions
Dosing details from the FDA-approved label
From the Dolasetron prescribing information (“Dosage and Administration”). Doses are set by your prescriber for your product, condition, kidney function and age — never change a dose on your own.
- Adults (prevention of nausea and vomiting with chemotherapy)
- 100 mg orally given within one hour before chemotherapy
- The recommended doses of ANZEMET Tablets should not be exceeded
- Pediatric patients 2 to 16 years of age
- 1.8 mg/kg orally given within one hour before chemotherapy
- Maximum: 100 mg
- For children for whom 100 mg is not appropriate based on weight or ability to swallow tablets, ANZEMET Injection solution may be mixed into apple or apple-grape juice for oral dosing; diluted product may be kept up to 2 hours at room temperature before use. Safety and effectiveness under 2 years not established
- Elderly, renal failure, or hepatically impaired patients
- No dosage adjustment is recommended
- ECG monitoring is recommended for elderly and renally impaired patients
Read the label’s full dosing text
DOSAGE AND ADMINISTRATION The recommended doses of ANZEMET Tablets should not be exceeded. Adults The recommended oral dosage of ANZEMET (dolasetron mesylate) is 100 mg given within one hour before chemotherapy. Pediatric Patients The recommended oral dosage in pediatric patients 2 to 16 years of age is 1.8 mg/kg given within one hour before chemotherapy, up to a maximum of 100 mg. Safety and effectiveness in pediatric patients under 2 years of age have not been established. In children for whom 100 mg is not appropriate based on their weight or ability to swallow tablets, the ANZEMET Injection solution may be mixed into apple or apple-grape juice for oral dosing in pediatric patients. The diluted product may be kept up to 2 hours at room temperature before use. However, ANZEMET Injection solution when administered intravenously is contraindicated in adult and pediatric patients for the prevention of nausea and vomiting associated with initial and repeat courses of emetogenic cancer chemotherapy due to dose dependent QT prolongation. Use in the Elderly, Renal Failure Patients, or Hepatically Impaired Patients No dosage adjustment is recommended, however; ECG monitoring is recommended for elderly and renally impaired patients (see WARNINGS and CLINICAL PHARMACOLOGY, Pharmacokinetics in Humans ).
Read the full Dosage and Administration section on DailyMed →
Dolasetron side effects
▾
The most commonly reported side effects with Anzemet Tablets include:
Common side effects
- Headache
- Fatigue
- Diarrhea
- Dizziness
- Slow heartbeat (bradycardia)
- Fast heartbeat (tachycardia)
- Upset stomach (dyspepsia)
- Chills or shivering
When to get medical help
- Call your doctor right away if you feel your heart racing, pounding, or beating irregularly
- Seek immediate help if you faint or feel like you might pass out
- Get emergency care if you develop signs of serotonin syndrome: agitation, hallucinations, fever, fast heart rate, muscle stiffness or twitching
- Tell your doctor immediately if you have chest pain or severe dizziness
- Contact your doctor if you develop an allergic reaction — such as rash, swelling of the face, or difficulty breathing
More serious reactions — including dangerous heart rhythm changes, fainting, and signs of serotonin syndrome (agitation, muscle twitching, fever, rapid heart rate) — should be treated as medical emergencies. Contact your care team or call 911 right away if these occur.
Dolasetron warnings and precautions
▾
- Heart rhythm (QT prolongation): Dolasetron prolongs the QT interval in a dose-related way, which can trigger a dangerous arrhythmia called Torsade de Pointes. Avoid it if you have congenital long QT syndrome, or low potassium or magnesium levels — these must be corrected first.
- PR and QRS prolongation: Dolasetron can also slow other parts of the heart's electrical system. Serious events including second- or third-degree heart block, cardiac arrest, and life-threatening arrhythmias have been reported. People with structural heart disease, sick sinus syndrome, atrial fibrillation, myocardial ischemia, or complete heart block are at highest risk.
- ECG monitoring: Recommended for elderly patients, those with renal impairment, congestive heart failure, bradycardia, or any significant conduction abnormality.
- Serotonin syndrome: Using dolasetron with other serotonergic drugs can cause serotonin syndrome — a potentially fatal reaction. Watch for agitation, hallucinations, fever, fast heart rate, muscle rigidity, or loss of coordination. Seek immediate care if these occur.
- Hypersensitivity: Do not take if you have a known allergy to dolasetron.
Dolasetron interactions
▾
Dolasetron's overall interaction risk is considered low, but some combinations require caution:
- QT-prolonging drugs (e.g., flecainide, quinidine): combining these with dolasetron increases the risk of dangerous heart rhythm problems
- PR-prolonging drugs (e.g., verapamil): increases risk of heart conduction slowing
- Cimetidine (heartburn drug): raises blood levels of dolasetron's active form by about 24%
- Rifampin (antibiotic): lowers blood levels of dolasetron's active form by about 28%, which could reduce its effectiveness
- Serotonergic drugs (SSRIs, SNRIs, MAO inhibitors, tramadol, lithium, mirtazapine, fentanyl, intravenous methylene blue): significantly raise the risk of serotonin syndrome
- Drugs or conditions causing low potassium or magnesium (e.g., some diuretics): worsen the heart rhythm risks associated with dolasetron
Interactions listed in the FDA-approved label
From the Dolasetron prescribing information (“Drug Interactions”): what the manufacturer studied or reported to the FDA.
- Cimetidine: With oral dolasetron 200 mg once daily and cimetidine 300 mg four times daily for 7 days, hydrodolasetron AUC increased by 24% and maximum plasma concentration increased by 15%.
- Rifampin: With oral dolasetron 200 mg once daily and rifampin 600 mg once daily for 7 days, hydrodolasetron systemic exposure decreased by 28% and maximum plasma concentration decreased by 17%.
- Drugs that prolong ECG intervals and/or cause hypokalemia or hypomagnesemia (including chemotherapy drugs): These drugs may add to ECG interval prolongation or electrolyte effects when co-administered with ANZEMET. Caution should be exercised when co-administered.
- Furosemide, nifedipine, diltiazem, ACE inhibitors, verapamil, glyburide, propranolol, and various chemotherapy agents: No effect was shown on the clearance of hydrodolasetron.
- Atenolol: Clearance of hydrodolasetron decreased by about 27% when dolasetron mesylate was given intravenously concomitantly with atenolol.
- Cisplatin, 5-fluorouracil, doxorubicin, cyclophosphamide: Dolasetron mesylate did not inhibit the antitumor activity of these four chemotherapeutic agents in four murine models.
- Serotonergic drugs including SSRIs and SNRIs: Serotonin syndrome (altered mental status, autonomic instability, neuromuscular symptoms) has been described with concomitant use of 5-HT3 receptor antagonists and other serotonergic drugs.
Read the label’s full interactions text
Drug Interactions The potential for clinically significant drug-drug interactions posed by dolasetron and hydrodolasetron appears to be low for drugs commonly used in chemotherapy because hydrodolasetron is eliminated by multiple routes. See PRECAUTIONS, General for information about potential interaction with other drugs that prolong the QT c interval. When oral dolasetron (200 mg once daily) was co-administered with cimetidine (300 mg four times daily) for 7 days, the systemic exposure (i.e., AUC) of hydrodolasetron increased by 24% and the maximum plasma concentration of hydrodolasetron increased by 15%. When oral dolasetron (200 mg once daily) was co-administered with rifampin (600 mg once daily) for 7 days, the systemic exposure of hydrodolasetron decreased by 28% and the maximum plasma concentration of hydrodolasetron decreased by 17%. Caution should be exercised when ANZEMET is co-administered with drugs, including those used in chemotherapy, that prolong ECG intervals and/or cause hypokalemia or hypomagnesemia (see WARNINGS ). In patients taking furosemide, nifedipine, diltiazem, ACE inhibitors, verapamil, glyburide, propranolol, and various chemotherapy agents, no effect was shown on the clearance of hydrodolasetron. Clearance of hydrodolasetron decreased by about 27% when dolasetron mesylate was administered intravenously concomitantly with atenolol. Dolasetron mesylate did not inhibit the antitumor activity of four chemotherapeutic agents (cisplatin, 5-fluorouracil, doxorubicin, cyclophosphamide) in four murine models. 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 re-uptake inhibitors (SSRIs) and serotonin and noradrenaline re-uptake inhibitors (SNRIs).
Not a complete list. The label covers the interactions the manufacturer studied or reported, and our own interaction database does not cover every medicine either. Bring your full medication list, including vitamins and herbal products, to your pharmacist.
Before taking Dolasetron
▾
- Tell your doctor if you have any heart condition — especially long QT syndrome, heart block, sick sinus syndrome, atrial fibrillation, myocardial ischemia, or congestive heart failure
- Tell your doctor if you have kidney impairment — ECG monitoring is recommended
- Tell your doctor if you are elderly — QT prolongation risk is higher and ECG monitoring may be needed
- Tell your doctor about ALL medications you take, especially antidepressants, anti-arrhythmic drugs, or any drug that affects heart rhythm
- Low potassium or magnesium levels must be corrected before you start this medication
- Do not take Anzemet if you have a known allergy to dolasetron
- Anzemet Tablets have not been studied in children under 2 years of age and are not recommended for that age group
- Tell your doctor if you have liver problems — while no dose adjustment is required, your doctor should know your full history
Dolasetron overdose
▾
There is no specific antidote for a dolasetron overdose. If an overdose is suspected, treatment is supportive — meaning doctors will manage symptoms as they appear. Heart rhythm changes (including prolonged PR, QRS, and QT intervals) are the main concern with excessive doses, and cardiac monitoring may be needed.
What Dolasetron does in the body
▾
Dolasetron selectively blocks 5-HT3 serotonin receptors and has very low affinity for dopamine receptors. In clinical studies, it did not affect pupil size, EEG brain wave patterns, mood, concentration, colonic movement, or prolactin hormone levels. At higher doses, it prolongs the QT, PR, and QRS intervals on an ECG — effects that are dose-dependent and primarily linked to its active metabolite, hydrodolasetron.
How your body processes Dolasetron
▾
After you take an Anzemet Tablet, dolasetron is rapidly and almost completely converted in the body to its active form, hydrodolasetron. This active metabolite reaches peak blood levels in about one hour and has a mean half-life of roughly 8 hours — meaning it takes about that long for half of it to leave your system. About 75% of the oral dose is effectively absorbed (bioavailability), and food does not change this. The body clears hydrodolasetron mainly through the kidneys (about two-thirds) and through the feces (about one-third).
How to store Dolasetron
▾
Store at 68° to 77°F (20° to 25°C) . Protect from light.
Written from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
Supplements & herbs that interact with Dolasetron
169 supplements and herbal products have documented interactions with Dolasetron in the licensed clinical database we use. Most are manageable — but your pharmacist should know about everything you take, including vitamins and herbals.
- Major · 4
- Moderate · 123
- Minor · 42
Educational information from a licensed clinical database (Natural Medicines) — see our data sources & update cadence. Not medical advice: an interaction being documented does not mean it will happen to you; do not start or stop medications or supplements without professional guidance.
Dolasetron: pharmacist answers to common questions
Quick, plain-English answers to the questions patients ask most about Dolasetron — the kind of thing our pharmacy team would talk through with you at the counter.
What exactly is Anzemet for, and when do I take it?
▾
Can I take Anzemet with food, or does it need to be on an empty stomach?
▾
What side effects should I watch out for?
▾
I take an antidepressant — is that a problem with Anzemet?
▾
I have a heart condition — is Anzemet safe for me?
▾
My child is having chemotherapy — can kids take Anzemet Tablets?
▾
Is Dolasetron available over the counter?
▾
When was Dolasetron first available?
▾
Answers drafted from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
More about Dolasetron on HelloPharmacist
Dolasetron on the U.S. market: products, makers and brands
How Dolasetron appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.
The FDA lists Dolasetron products; the earliest marketing or approval year on record is 1997. Brand names on the directory include Anzemet; the rest are generics.
Also listed with the FDA, not a patient dose form: Powder (3) — bulk drug substance sold to compounders/manufacturers and multi-item kits. These aren’t counted in the dose-form total above.
Dolasetron side effects reported to the FDA (FAERS)
After a medicine reaches the market, patients, doctors and drugmakers can send the FDA reports of problems they think may be linked to it. Here’s what’s been reported for Dolasetron — a signal of what to watch for, not proof the drug caused it.
Source: openFDA, from the FDA Adverse Event Reporting System (FAERS). These are voluntary reports — they don’t prove the drug caused the effect, and counts reflect how often something was reported, not how often it actually happens. Reports also often name the very problem the medicine is taken for — a common reason to file one is that the drug didn’t help — so for a pain reliever you may see “pain” high on the list; that points to why the report was filed, not to the drug causing the symptom. This counts every report that lists Dolasetron in any role, so the total runs higher than the FDA’s official dashboard, which counts only cases where the drug is the suspect. For the authoritative figures, see the FDA FAERS Public Dashboard. Always talk to your pharmacist or doctor.
Dolasetron FDA approval history
How Dolasetron went from FDA review to the pharmacy shelf — the key milestones in its regulatory journey.
Dolasetron was first approved by the FDA in 1997 (Brand: ANZEMET · Validus Pharms). It remains available in U.S. pharmacies today.
Source: Drugs@FDA.
Dolasetron recall history
A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.
The FDA’s enforcement reports list no Dolasetron recalls since July 2021.
✅No Dolasetron recalls on record since July 2021Source: FDA enforcement (recall) reports, via openFDA; our copy was last updated Sep 24, 2026.
RxNorm Concept Web — From Ingredient to Every Form and Strength
This page starts with one ingredient concept (IN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). Combination products remain separate concepts with their own pages.
RxCUI 68091 1 dose form · 3 strengths
-
Dose form (SCDF) Oral Tablet RxCUI 371951No current FDA listingClinical drug / strength (SCD) 50 MGRxCUI 310007100 MGRxCUI 310006200 MGRxCUI 401714
Look up RxCUI 68091 in the RxCUI Atlas →
RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.
Dolasetron supply and shortage status
Whether Dolasetron is in short supply in the U.S. right now, plus any shortage history the FDA has on record. A shortage usually reflects a manufacturing or demand issue — not a safety problem with the drug.
Source: openFDA, from the FDA Drug Shortages database.
Dolasetron brand names
Dolasetron is sold under one brand name in the FDA directory — Anzemet. A brand and its generic contain the same active ingredient; the brand name belongs to one company's product.
Dolasetron drug class (RxNorm)
Dolasetron belongs to the Serotonin-3 Receptor Antagonist class.
Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.
Sources for this Dolasetron page
Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.
How this page is built
HelloPharmacist combines public FDA and NLM records and does not author the underlying clinical facts. The plain-language sections are written with AI from the FDA-approved label text and reviewed by our pharmacy team before publication. Validus Pharmaceuticals LLC is the representative DailyMed label linked for verification and dates. This is general education, not medical advice: always talk to your doctor or pharmacist about your own medicines. How we build and review drug pages →