What the label lists and what reports show
Clobazam side effects
Clobazam's FDA label: “Most Common Adverse Reactions in an LGS Placebo Controlled Clinical Trial (Study 1) Table 3 lists the adverse reactions that occurred in ≥5% of ONFI-treated patients (at any dose), and at a rate greater than placebo-treated patients, in the randomized …” FAERS holds 24,270 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 somnolence (1,944 reports).
- Generic listed
- Boxed warning
- DEA Schedule IV
Check it at the source: the clobazam FDA label on DailyMed (effective March 12, 2024, Lundbeck Pharmaceuticals 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 ONFI?ONFI may cause serious side effects, including: See "What is the most important information I should know about ONFI?" The most common side effects of ONFI include: sleepiness drooling constipation cough pain with urination fever acting aggressive, being angry, or violent difficulty sleeping slurred speech tiredness problems with breathing These are not all the possible side effects of ONFI. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
Source: FDA drug label, Lundbeck Pharmaceuticals LLC, effective March 12, 2024 (SPL set de03bd69-2dca-459c-93b4-541fd3e9571c), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsMost Common Adverse Reactions in an LGS Placebo Controlled Clinical Trial (Study 1) Table 3 lists the adverse reactions that occurred in ≥5% of ONFI-treated patients (at any dose), and at a rate greater than placebo-treated patients, in the randomized, double-blind, placebo-controlled, parallel group clinical study of adjunctive AED therapy for 15 weeks (Study 1).
Table 3. Adverse Reactions Reported for ≥5% of Patients and More Frequently than Placebo in Any Treatment Group
This table is printed in the Clobazam label published by Lupin Pharmaceuticals, Inc. of October 31, 2025; the label quoted above does not print one.
| Reaction | Placebo N=59 % | Low a N=58 % | Medium b N=62 % | High c N=59 % | All Clobazam N=179 % |
|---|---|---|---|---|---|
| Vomiting | 5 | 9 | 5 | 7 | 7 |
| Constipation | 0 | 2 | 2 | 10 | 5 |
| Dysphagia | 0 | 0 | 0 | 5 | 2 |
| Pyrexia | 3 | 17 | 10 | 12 | 13 |
| Irritability | 5 | 3 | 11 | 5 | 7 |
| Fatigue | 2 | 5 | 5 | 3 | 5 |
| Upper respiratory tract infection | 10 | 10 | 13 | 14 | 12 |
| Pneumonia | 2 | 3 | 3 | 7 | 4 |
| Urinary tract infection | 0 | 2 | 5 | 5 | 4 |
| Bronchitis | 0 | 2 | 0 | 5 | 2 |
| Decreased appetite | 3 | 3 | 0 | 7 | 3 |
| Increased appetite | 0 | 2 | 3 | 5 | 3 |
| Somnolence or Sedation | 15 | 17 | 27 | 32 | 26 |
| Somnolence | 12 | 16 | 24 | 25 | 22 |
| Sedation | 3 | 2 | 3 | 9 | 5 |
| Lethargy | 5 | 10 | 5 | 15 | 10 |
| Drooling | 3 | 0 | 13 | 14 | 9 |
| Ataxia | 3 | 3 | 2 | 10 | 5 |
| Psychomotor hyperactivity | 3 | 3 | 3 | 5 | 4 |
| Dysarthria | 0 | 2 | 2 | 5 | 3 |
| Aggression | 5 | 3 | 8 | 14 | 8 |
| Insomnia | 2 | 2 | 5 | 7 | 5 |
| Cough | 0 | 3 | 5 | 7 | 5 |
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, continuedClinically significant adverse reactions that appear in other sections of the labeling include the following: Risks from Concomitant Use with Opioids [see Warnings and Precautions ( 5.1 )] Abuse, Misuse, and Addiction [see Warnings and Precautions ( 5.2 )] Dependence and Withdrawal Reactions [see Warnings and Precautions ( 5.3 )] Potentiation of Sedation from Concomitant Use with Central Nervous System Depressants [see Warnings and Precautions ( 5.4 )] Somnolence or Sedation [see Warnings and Precautions ( 5.5 )] Serious Dermatological Reactions [see Contraindications ( 4 ), Warnings and Precautions ( 5.6 )] Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)/Multiorgan Hypersensitivity [see Warnings and Precautions ( 5.7 )] Suicidal Behavior and Ideation [see Warnings and Precautions ( 5.8) ] Neonatal Sedation and Withdrawal Syndrome [see Warnings and Precautions ( 5.9) ] Adverse reactions that occurred at least 10% more frequently than placebo in any ONFI dose included constipation, somnolence or sedation, pyrexia, lethargy, and drooling ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Lundbeck at 1-800-455-1141 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. …
Source: FDA drug label, Lundbeck Pharmaceuticals LLC, effective March 12, 2024 (SPL set de03bd69-2dca-459c-93b4-541fd3e9571c), via openFDA; the full label on DailyMed
What do FAERS reports show?
24,270 reports list clobazam among the medicines taken, each a report of something that happened, not proof the medicine caused it; 1,565 are coded as a death and 8,270 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 16 reactions below, 9 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?
- Clobazam: 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