Celontin Side Effects

Generic name: methsuximide

Medically reviewed by Drugs.com. Last updated on Jul 13, 2023.

Note: This document contains side effect information about methsuximide. Some dosage forms listed on this page may not apply to the brand name Celontin.

Applies to methsuximide: oral capsule.

Serious side effects of Celontin

Along with its needed effects, methsuximide (the active ingredient contained in Celontin) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking methsuximide:

Rare

Attempts at killing oneself
feeling that others are watching you or controlling your behavior
feeling that others can hear your thoughts
feeling, seeing, or hearing things that are not there
severe mood or mental changes
unusual behavior

Incidence not known

Attack, assault, or force
blistering, peeling, or loosening of the skin
blood in the urine
bloody, black, or tarry stools
chest pain
chills
cloudy urine
cough or hoarseness
diarrhea
discouragement
feeling sad or empty
fever
high fever
irritability
itching
joint or muscle pain
lack of appetite
loss of interest or pleasure
lower back or side pain
mood or mental changes
nervousness
painful or difficult urination
pale skin
red skin lesions, often with a purple center
red, irritated eyes
shakiness and unsteady walk
shortness of breath
sore throat
sores, ulcers, or white spots on the lips or in the mouth
swelling around the eyes
swollen glands
tiredness
trouble with concentrating
trouble with sleeping
unexplained bleeding or bruising
unsteadiness, trembling, or other problems with muscle control or coordination
unusual bleeding or bruising
unusual tiredness or weakness
vision changes

Get emergency help immediately if any of the following symptoms of overdose occur while taking methsuximide:

Symptoms of overdose

Change in consciousness
difficult or troubled breathing
irregular, fast or slow, or shallow breathing
loss of consciousness
pale or blue lips, fingernails, or skin

Other side effects of Celontin

Some side effects of methsuximide may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Incidence not known

Blurred vision
change in color vision
difficulty having a bowel movement (stool)
difficulty seeing at night
dizziness
drowsiness
heartburn
hiccups
hives or welts
increased sensitivity of the eyes to sunlight
loss of appetite
nausea or vomiting
pain or discomfort in the chest, upper stomach, or throat
redness of the skin
skin rash
sleeplessness
unable to sleep
weight loss

For Healthcare Professionals

Applies to methsuximide: oral capsule.

General

The more frequently reported adverse events have included gastrointestinal symptoms such as nausea, vomiting, and anorexia and neurologic reactions such as drowsiness, dizziness and headache.

Gastrointestinal

Frequency not reported: Nausea, vomiting, anorexia, diarrhea, weight loss, epigastric and abdominal pain, constipation, hiccups^[Ref]

Nervous system

Frequency not reported: Drowsiness, ataxia, dizziness, headache^[Ref]

Psychiatric

Rare (less than 0.1%): Psychosis, suicidal behavior, auditory hallucinations

Frequency not reported: Confusion, instability, mental slowness, depression, hypochondriacal behavior, aggressiveness, irritability, nervousness, insomnia.^[Ref]