What the label lists and what reports show
Stiripentol side effects
Stiripentol's FDA label: “The most common adverse reactions, occurring in at least 10% of DIACOMIT-treated patients and more frequently than on placebo, included somnolence (67%), decreased appetite (45%), agitation (27%), ataxia (27%), weight decreased (27%), hypotonia (24%), nausea …” FAERS holds 2,141 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 decreased appetite (254 reports).
- No generic listed
Check it at the source: the stiripentol FDA label on DailyMed (effective April 27, 2026, BIOCODEX, INC.); 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 DIACOMIT?DIACOMIT may cause serious side effects, including: See “What is the most important information I should know about DIACOMIT?” The most common side effects of DIACOMIT include: agitation loss of control of body movements (ataxia) low muscle tone or muscle weakness (hypotonia) nausea tremor trouble saying words clearly (dysarthria) trouble sleeping (insomnia) These are not all the possible side effects of DIACOMIT. For more information, ask your healthcare provider or pharmacist. Tell your healthcare provider if you have any side effect that bothers you or that does not go away. 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, BIOCODEX, INC., effective April 27, 2026 (SPL set 58304ba8-9779-4658-811e-94ffe08c3f16), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsThe most common adverse reactions, occurring in at least 10% of DIACOMIT-treated patients and more frequently than on placebo, included somnolence (67%), decreased appetite (45%), agitation (27%), ataxia (27%), weight decreased (27%), hypotonia (24%), nausea (15%), tremor (15%), dysarthria (12%), and insomnia (12%).
Table 3. Adverse Reactions in 5% or More of DIACOMIT-Treated Patients and More Frequently than on Placebo in Patients with Dravet Syndrome (Sticlo France and Sticlo Italy)
| Adverse Reactions | DIACOMIT (50mg/kg/day) N=33 % | Placebo N=31 % |
|---|---|---|
| Nausea | 15 | 3 |
| Vomiting | 9 | 0 |
| Salivary hypersecretion | 6 | 0 |
| Fatigue | 9 | 3 |
| Pyrexia | 6 | 3 |
| Bronchitis | 6 | 0 |
| Nasopharyngitis | 6 | 0 |
| Weight decreased | 27 | 6 |
| Weight increased | 6 | 3 |
| Decreased appetite | 46 | 10 |
| Somnolence | 67 | 23 |
| Ataxia | 27 | 23 |
| Hypotonia | 18 | 13 |
| Tremor | 15 | 10 |
| Dysarthria | 12 | 0 |
| Agitation | 27 | 16 |
| Insomnia | 12 | 7 |
| Aggression | 9 | 0 |
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 serious or otherwise clinically significant adverse reactions are described elsewhere in the labeling: Somnolence [see Warnings and Precautions (5.1) ] Decreased Appetite and Decreased Weight [see Warnings and Precautions (5.2) ] Neutropenia and Thrombocytopenia [see Warnings and Precautions (5.3) ] Withdrawal Symptoms [see Warnings and Precautions (5.4) ] Risks in Patients with Phenylketonuria [see Warnings and Precautions (5.5) ] Suicidal Behavior and Ideation [see Warnings and Precautions (5.6) ] Adverse reactions that occurred in at least 10% of DIACOMIT-treated patients and more frequently than on placebo were somnolence, decreased appetite, agitation, ataxia, weight decreased, hypotonia, nausea, tremor, dysarthria, and insomnia. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact BIOCODEX at 1-866-330-3050 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 clinical trials of another drug, and may not reflect the rates observed in practice. …
Source: FDA drug label, BIOCODEX, INC., effective April 27, 2026 (SPL set 58304ba8-9779-4658-811e-94ffe08c3f16), via openFDA; the full label on DailyMed
What do FAERS reports show?
2,141 reports list stiripentol among the medicines taken, each a report of something that happened, not proof the medicine caused it; 108 are coded as a death and 723 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 15 reactions below, 11 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?
- Stiripentol: 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