What is Celontin used for?

Celontin is indicated for Absence seizure, Epilepsy.

Celontin is developed by Pfizer.

What development phase is Celontin in?

Celontin is FDA-approved (marketed).

What are the side effects of Celontin?

Common side effects include Nausea or vomiting, Drowsiness, Ataxia or dizziness, Diarrhea, Weight loss, Epigastric and abdominal pain.

What is the generic name of Celontin?

METHSUXIMIDE is the generic (nonproprietary) name of Celontin.

Last reviewed 2026-04-20 · How we verify

Celontin (METHSUXIMIDE)

Pfizer · FDA-approved approved Small molecule

Celontin works by blocking the activity of voltage-gated T-type calcium channels in the brain.

Celontin (METHSUXIMIDE) is a small molecule anti-epileptic agent developed by Parke Davis, targeting voltage-gated T-type calcium channels. It was FDA-approved in 1957 for the treatment of absence seizures and epilepsy. As an off-patent medication, Celontin is available as a generic product. Key considerations for its use include its mechanism of action and potential side effects. Celontin's commercial status allows for generic competition.

At a glance

Generic name	METHSUXIMIDE
Sponsor	Pfizer
Drug class	Anti-epileptic Agent
Target	Voltage-gated T-type calcium channel
Modality	Small molecule
Therapeutic area	Neuroscience
Phase	FDA-approved
First approval	1957

Mechanism of action

Think of your brain as a city with many doors. These doors, called channels, control what comes in and out. Celontin blocks one type of door, called T-type calcium channels, which helps to reduce the abnormal electrical activity that can cause seizures.

Approved indications

Absence seizure
Epilepsy

Common side effects

Nausea or vomiting
Drowsiness
Ataxia or dizziness
Diarrhea
Weight loss
Epigastric and abdominal pain
Constipation
Leukopenia
Monocytosis
Pancytopenia with or without bone marrow suppression
Eosinophilia
Headache

Key clinical trials

Population Pharmacokinetics of Antiepileptic in Pediatrics

Primary sources

Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.

Source	Used for
FDA label	Mechanism, indications, dosing, boxed warnings, drug interactions
ClinicalTrials.gov	Trial enrolment, design, endpoints, results

Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:

Celontin CI brief — competitive landscape report
Celontin updates RSS · CI watch RSS
Pfizer portfolio CI