What the label lists and what reports show
Riluzole side effects
Riluzole's FDA label: “Most common adverse reactions (incidence greater than or equal to 5% and greater than placebo) were asthenia, nausea, dizziness, decreased lung function, and abdominal pain ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Glenmark Pharmaceuticals Inc. …” FAERS holds 2,164 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 nausea (153 reports).
- Generic listed
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Check it at the source: the riluzole FDA label on DailyMed (effective July 10, 2020, Glenmark Pharmaceuticals Inc., USA); the FDA FAERS public dashboard.
What does the label list?
From the label: adverse reactionsMost common adverse reactions (incidence greater than or equal to 5% and greater than placebo) were asthenia, nausea, dizziness, decreased lung function, and abdominal pain ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Glenmark Pharmaceuticals Inc., USA at 1 (888) 721-7115 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
A table the label prints in its adverse reactions section without a title; its column headings name the groups compared
| Reaction | Riluzole 50 mg twice daily (N=313) | Placebo (N=320) |
|---|---|---|
| Asthenia | 19% | 12% |
| Nausea | 16% | 11% |
| Decreased lung function | 10% | 9% |
| Hypertension | 5% | 4% |
| Abdominal pain | 5% | 4% |
| Vomiting | 4% | 2% |
| Arthralgia | 4% | 3% |
| Dizziness | 4% | 3% |
| Dry mouth | 4% | 3% |
| Insomnia | 4% | 3% |
| Pruritus | 4% | 3% |
| Tachycardia | 3% | 1% |
| Flatulence | 3% | 2% |
| Increased cough | 3% | 2% |
| Peripheral edema | 3% | 2% |
| Urinary Tract Infection | 3% | 2% |
| Circumoral paresthesia | 2% | 0% |
| Somnolence | 2% | 1% |
| Vertigo | 2% | 1% |
| Eczema | 2% | 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, continuedThe following adverse reactions are described below and elsewhere in the labeling: • Hepatic Injury [see Warnings and Precautions ( 5.1 )] • Neutropenia [see Warnings and Precautions ( 5.2 )] • Interstitial lung disease [see Warnings and Precautions ( 5.3 )] Most common adverse reactions (incidence greater than or equal to 5% and greater than placebo) were asthenia, nausea, dizziness, decreased lung function, and abdominal pain ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Glenmark Pharmaceuticals Inc., USA at 1 (888) 721-7115 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 practice. Adverse Reactions in Controlled Clinical Trials In the placebo-controlled clinical trials in patients with ALS (Study 1 and 2), a total of 313 patients received riluzole 50 mg twice daily [see Clinical Studies ( 14 )]. The most common adverse reactions in the riluzole group (in at least 5% of patients and more frequently than in the placebo group) were asthenia, nausea, dizziness, decreased lung function, and abdominal pain. …
Source: FDA drug label, Glenmark Pharmaceuticals Inc., USA, effective July 10, 2020 (SPL set f1ce57e8-d3fe-422c-8724-3101c258898a), via openFDA; the full label on DailyMed
What do FAERS reports show?
2,164 reports list riluzole among the medicines taken, each a report of something that happened, not proof the medicine caused it; 500 are coded as a death and 517 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 19 reactions below, 4 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?
- Riluzole: 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