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Methsuximide Side Effects

The most commonly reported side effects of methsuximide include seizure, generalised tonic-clonic seizure, and off label use, based on 178 FDA adverse event reports from 2004 to 2025. 12.9% of reports found the drug to be ineffective.

Methsuximide side effects

Percentages show how often each reaction appears relative to total reports for methsuximide.

1
Drug Ineffective12.9%23
2
Seizure11.2%20
3
Generalised Tonic-clonic Seizure6.2%11
4
Off Label Use6.2%11
5
Convulsion5.6%10
6
Somnolence5.6%10
7
Dizziness4.5%8
8
Drug Interaction3.9%7
9
Feeling Abnormal3.9%7
10
Asthenia3.9%7
11
Therapeutic Product Effect Incomplete3.9%7
12
Toxicity To Various Agents3.4%6
13
Tremor3.4%6
14
Nausea2.8%5
15
Fall2.8%5

These are voluntary reports and do not establish that methsuximide caused these reactions.

Report severity

60.1%Serious107 reports
21.9%Hospitalizations39 reports
1.1%Fatal2 reports

Seriousness is determined by the reporter, not by OpenClaim.

Methsuximide drug interactions

Other drugs that appear in adverse event reports alongside methsuximide. Drugs flagged as a suspected cause appear in the first column. Drugs taken at the same time but not suspected appear in the second.

Also suspected

1
Phenytoin16.3%29
2
Vigabatrin10.1%18
3
Levetiracetam9.6%17
4
Clobazam7.9%14
5
Cannabidiol7.9%14
6
Primidone7.3%13
7
Valproic-acid6.7%12
8
Lamotrigine6.7%12
9
Pregabalin6.2%11
10
Topiramate6.2%11
11
Lacosamide5.6%10
12
Phenobarbital-sodium5.6%10
13
Zonisamide5.1%9
14
Divalproex-sodium3.9%7
15
Everolimus3.9%7

Taken alongside

1
Primidone9.0%16
2
Zonisamide9.0%16
3
Clobazam8.4%15
4
Phenytoin7.3%13
5
Lamotrigine7.3%13
6
Rufinamide7.3%13
7
Clonazepam6.7%12
8
Divalproex-sodium6.7%12
9
Phenobarbital-sodium6.7%12
10
Gabapentin5.6%10
11
Diazepam5.6%10
12
Lacosamide5.6%10
13
Acetaminophen4.5%8
14
Levetiracetam4.5%8
15
Ondansetron3.9%7

Co-occurrence in adverse event reports does not establish a drug interaction. Patients often take multiple medications, and these lists reflect prescribing patterns rather than causal relationships. Consult a healthcare provider about potential drug interactions.

Who reports methsuximide side effects

46.1% of methsuximide adverse event reports involve female patients and 41.0% involve male patients. The largest age group is adult at 53%. These figures reflect who reports side effects, not underlying risk.

Sex

Female46.1%
Male41.0%
Unknown12.9%

Age group

< 20.9%
2–1114.7%
12–177.3%
18–6453.2%
65+23.9%

What is methsuximide used for

Conditions and purposes for which patients were taking methsuximide when the adverse event was reported.

Ankle Brachial IndexConvulsionClonic ConvulsionEpilepsyEpilepsia Partialis ContinuaEpilepsyEssential HypertensionEyelid MyoclonusFocal Dyscognitive SeizuresGeneralised Tonic-clonic SeizureGrand Mal ConvulsionGeneralised Tonic-clonic SeizureHyperlipidaemiaIntermittent ClaudicationPartial Seizures

Showing 15 of 26 indications

Methsuximide brand names and reporting trend

Methsuximide is sold under the brand name Methsuximide.

Brand names

Methsuximide44

Quarterly reports (20042025)

20042010201520202025

An upward trend reflects increased FAERS reporting overall, not necessarily increased risk.

Taking methsuximide with another medication?

Ask OpenClaim about your specific drug combination. Get a sourced report using FDA data, drug labels, and medical literature.