What the label lists and what reports show
Granisetron side effects
Granisetron's FDA label: “Most common adverse reactions: • Chemotherapy-induced nausea and vomiting (≥3%): Headache, and constipation ( 6.1 ) • Postoperative nausea and vomiting (≥2%): Pain, headache, fever, abdominal pain and hepatic enzymes increased ( 6.1 ) To report SUSPECTED …” FAERS holds 12,067 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is febrile neutropenia (879 reports).
- Generic listed
Check it at the source: the granisetron FDA label on DailyMed (effective August 31, 2017, Mylan Institutional LLC); the FDA FAERS public dashboard.
What does the patient leaflet say about side effects?
From the patient leaflet: What are the possible side effects of SUSTOL?SUSTOL may cause serious side effects, including: See " What is the most important information I should know about SUSTOL? " Serotonin Syndrome. A possible life-threatening problem called serotonin syndrome can happen with medicines called 5-HT 3 receptor antagonists, including SUSTOL, especially when used with medicines used to treat depression and migraine headaches called serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), monoamine oxidase inhibitors (MAOIs), and certain other medicines. […]
Source: FDA drug label (SUSTOL), Heron Therapeutics, Inc., effective April 30, 2026 (SPL set f7c7ffdd-8270-4030-bc1e-a1cb28a6de56), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsMost common adverse reactions: • Chemotherapy-induced nausea and vomiting (≥3%): Headache, and constipation ( 6.1 ) • Postoperative nausea and vomiting (≥2%): Pain, headache, fever, abdominal pain and hepatic enzymes increased ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Mylan Pharmaceuticals Inc.at 1-877-446-3679 (1-877-4-INFO-RX) or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
Table 2 Adverse Reactions in Controlled Clinical Trials in Postoperative Nausea and Vomiting (Reported in ≥ 2% of Adults Receiving Granisetron Hydrochloride Injection 1 mg)
This table is printed in the Granisetron Hydrochloride label published by Eugia US LLC of April 24, 2025; the label quoted above does not print one.
| Reaction | Granisetron Hydrochloride Injection 1 mg (n=267) | Placebo (n=266) |
|---|---|---|
| Pain | 10.1 | 8.3 |
| Headache | 8.6 | 7.1 |
| Fever | 7.9 | 4.5 |
| Abdominal Pain | 6 | 6 |
| Hepatic Enzymes Increased | 5.6 | 4.1 |
| Dizziness | 4.1 | 3.4 |
| Diarrhea | 3.4 | 1.1 |
| Flatulence | 3 | 3 |
| Dyspepsia | 3 | 1.9 |
| Oliguria | 2.2 | 1.5 |
| Coughing | 2.2 | 1.1 |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
From the label: adverse reactions, continuedQT prolongation has been reported with granisetron hydrochloride [ see Warnings and Precautions (5.2) and Drug Interactions (7) ]. Most common adverse reactions: • Chemotherapy-induced nausea and vomiting (≥3%): Headache, and constipation ( 6.1 ) • Postoperative nausea and vomiting (≥2%): Pain, headache, fever, abdominal pain and hepatic enzymes increased ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Mylan Pharmaceuticals Inc.at 1-877-446-3679 (1-877-4-INFO-RX) or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical 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 to rates in the clinical trials of another drug and may not reflect the rates observed in patients. Chemotherapy-Induced Nausea and Vomiting The following have been reported during controlled clinical trials or in the routine management of patients. The percentage figures are based on clinical trial experience only. Table 1 gives the comparative frequencies of the two most commonly reported adverse reactions (≥3%) in patients receiving granisetron hydrochloride injection, in single-day chemotherapy trials. …
Source: FDA drug label, Mylan Institutional LLC, effective August 31, 2017 (SPL set 8d88adba-7f5e-4e97-84b3-6ca8ec98c023), via openFDA; the full label on DailyMed
What do FAERS reports show?
12,067 reports list granisetron among the medicines taken, each a report of something that happened, not proof the medicine caused it; 2,221 are coded as a death and 5,990 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 21 reactions below, 7 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Granisetron: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions