granisetron
Brand names: Kytril
Granisetron oral solution helps prevent nausea and vomiting caused by cancer treatments like chemotherapy and radiation. It belongs to a class of drugs called 5-HT3 receptor antagonists.
Drug Pricing (NADAC)
Generic Price
$1.39/unit
Generic Available
Yes (8 manufacturers)
Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →
What it does
Granisetron is used to prevent nausea and vomiting.
Common side effects
Headache, Constipation, Weakness or fatigue
Key warnings
Granisetron can cause a heart problem called QT prolongation.
How It Works
Granisetron blocks a natural substance called serotonin in the body. Serotonin can trigger nausea and vomiting. By blocking serotonin, granisetron helps prevent these side effects.
How to Take It
Take granisetron oral solution up to 1 hour before your chemotherapy or radiation treatment. The usual adult dose is 2 mg once a day, or 1 mg twice a day. If taking 2 mg once daily, measure 10 mL (2 teaspoonfuls). If taking 1 mg twice daily, measure 5 mL (1 teaspoonful) before treatment, and another 5 mL 12 hours later. Take this medicine only on the days you receive chemotherapy or radiation.
Pregnancy & Breastfeeding
Tell your doctor if you are pregnant or breastfeeding. It is not known if granisetron will harm an unborn baby. It is also not known if granisetron passes into breast milk.
Missed Dose
If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and continue with your regular schedule.
Storage
Store granisetron oral solution at room temperature (68° to 77°F), away from light, in a tightly closed, upright bottle.
Side Effects (from patient reports)
Based on 6,815 FDA adverse event reports.
FDA Adverse Event Report Analysis
Detailed analysis of 10,198 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2003–2025.
Total Reports
10,198
Death-Related Reports
1,855
Hospitalization Reports
4,892
Top Indication
Product Used For Unknown Indication
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 1 | NAUSEA | 1,305 |
| 2 | VOMITING | 754 |
| 3 | FEBRILE NEUTROPENIA | 718 |
| 4 | DIARRHOEA | 709 |
| 5 | PYREXIA | 641 |
| 6 | DEATH | 603 |
| 7 | DYSPNOEA | 592 |
| 8 | FATIGUE | 549 |
| 9 | NEUTROPENIA | 474 |
| 10 | ANAEMIA | 469 |
| 11 | OFF LABEL USE | 435 |
| 12 | PRODUCT ADHESION ISSUE | 399 |
| 13 | CONSTIPATION | 393 |
| 14 | DECREASED APPETITE | 368 |
| 15 | PNEUMONIA | 363 |
Reactions in Death Reports
Reactions in Hospitalization Reports
Source: FDA FAERS (Adverse Event Reporting System) FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation
Serious Warnings
Granisetron can cause a heart problem called QT prolongation. Tell your doctor if you take other medicines that can also cause this issue, as it could lead to serious heart problems.
Known Drug Interactions
In in vitro human microsomal studies, ketoconazole inhibited ring oxidation of granisetron. However, the clinical significance of in vivo pharmacokinetic interactions with ketoconazole is not known.
Mechanism: Ketoconazole might slow down how your liver processes granisetron, but doctors are not sure if this causes any real problems.
What to do: No specific dose changes are required, but you should report any new side effects to your healthcare provider.
In a human pharmacokinetic study, hepatic enzyme induction with phenobarbital resulted in a 25% increase in total plasma clearance of intravenous granisetron.
Mechanism: Phenobarbital makes your liver work faster to remove granisetron from your body.
What to do: Your doctor may need to monitor you to make sure granisetron is still working well enough to control your symptoms.
Intervention No dosage adjustment needed Examples ondansetron, granisetron, dolasetron 7.2 Effect of Other Drugs on the Pharmacokinetics of Aprepitant Aprepitant is a CYP3A4 substrate [see Clinical Pharmacology ( 12.3 )] . Intervention No dosage adjustment needed Examples ondansetron, granisetron, dolasetron 7.2 Effect of Other Drugs on the Pharmacokinetics of Aprepitant Aprepitant is a CYP3A4 substrate [see Clinical Pharmacology ( 12.3 )] .
Mechanism: These medicines do not significantly change how the body handles either drug.
What to do: You can take these medicines together without needing to adjust your dose.
Common Questions
Can I take granisetron every day?
Does granisetron interact with other medications?
What should I do if I experience side effects?
Can children take granisetron?
Do I need to adjust the dose if I have kidney or liver problems?
Can I drink alcohol while taking granisetron?
What does granisetron oral solution look like?
What if I accidentally take too much granisetron?
How long does granisetron take to work?
Can I drive or operate machinery while taking granisetron?
What are the common side effects of granisetron?
Does granisetron interact with other medications?
What drug class is granisetron?
Is granisetron safe during pregnancy?
Related Medications in 5-HT3 Receptor Antagonist (Antiemetic)
Other drugs grouped near granisetron — same-class peers and common alternatives.
alosetron
Lotronex
Alosetron (Lotronex) is a medicine for women with severe diarrhea-predominant irritable bowel syndrome (IBS).
Compare with granisetron →
aprepitant
Emend
Aprepitant (Emend) is a medicine that helps prevent nausea and vomiting.
Compare with granisetron →
bisacodyl
Dulcolax
Bisacodyl is a medicine that helps you have a bowel movement.
Compare with granisetron →
bismuth subsalicylate
Pepto-Bismol
Bismuth subsalicylate (Pepto-Bismol) is a medicine that can treat diarrhea and upset stomach.
Compare with granisetron →
cimetidine
Tagamet
Cimetidine (Tagamet) reduces stomach acid.
Compare with granisetron →
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What the FDA Data Shows for granisetron
The FDA label for granisetron (sold under brand names such as Kytril) classifies it as a prescription-only medication in the 5-HT3 Receptor Antagonist (Antiemetic) class. Granisetron is used to prevent nausea and vomiting. Official labeling lists 6 commonly reported side effects, including Headache, Constipation, Weakness or fatigue.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 6,815 voluntary reports. The database also lists 3 documented drug interactions derived from FDA labeling, with the top-flagged interaction rated minor severity. NADAC pricing from CMS shows a generic unit cost of $1.39.
Report counts do not establish causation — a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history, and patent information further shape supply and switching decisions. This page summarizes public FDA data for educational purposes only and is not a substitute for professional medical advice — always consult a licensed healthcare provider before starting, stopping, or changing any medication.
Data Sources
Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC).
FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. Always consult a healthcare professional before making medication decisions.
Last updated: March 21, 2025
Read our methodology — how this data is sourced, computed, and verified.
All federal data sources used on this page
- FDA Orange Book — approved drug products with therapeutic equivalence. accessdata.fda.gov/cder/ob
- FDA DailyMed — NIH-hosted drug labeling for FDA-approved meds. dailymed.nlm.nih.gov
- FDA Adverse Event Reporting System (FAERS) — post-marketing safety surveillance. fda.gov/drugs/faers
- NLM RxNorm — standardized clinical drug nomenclature. nlm.nih.gov/research/umls/rxnorm
- CMS Medicare Part B Drug Average Sales Price Files — federal drug pricing data. cms.gov/medicare/part-b-drugs/asp
- FDA Drug Shortages Database — current and resolved drug shortage tracking. accessdata.fda.gov/drugshortages