Cycloserine Side Effects

Medically reviewed by Drugs.com. Last updated on Dec 11, 2023.

Applies to cycloserine: oral capsule.

Serious side effects of cycloserine

Along with its needed effects, cycloserine 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 cycloserine:

More common side effects

• anxiety
• confusion
• dizziness
• drowsiness
• increased irritability
• increased restlessness
• mental depression
• muscle twitching or trembling
• nervousness
• nightmares
• other mood or mental changes
• speech problems
• thoughts of suicide

Less common side effects

• convulsions (seizures)
• numbness, tingling, burning pain, or weakness in the hands or feet
• skin rash

Other side effects of cycloserine

Some side effects of cycloserine 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:

More common side effects

• headache

For healthcare professionals

Applies to cycloserine: oral capsule.

General adverse events

The most commonly reported side effects included hypersensitivity and nervous system manifestations.^[Ref]

Nervous system

• Frequency not reported: Central nervous system toxicity, character changes, coma, convulsions, drowsiness, headache, hyperreflexia, major and minor (localized) clonic seizures, memory loss, paresis, paresthesia, somnolence, tremor, vertigo^[Ref]

Character changes, coma, convulsions, drowsiness, headache, hyperreflexia, major and minor (localized) clonic seizures, memory loss, paresis, paresthesia, somnolence, tremor, vertigo appeared to be dose related.^[Ref]

Psychiatric

• Frequency not reported: Aggression, anxiety, confusion, disorientation, dysarthria, hyperirritability, psychosis with/without suicidal tendencies^[Ref]

Aggression, confusion, disorientation, dysarthria, hyperirritability, and psychosis with/without suicidal tendencies appeared to be dose related.^[Ref]

Hypersensitivity

• Frequency not reported: Allergic dermatitis, allergy, drug hypersensitivity^[Ref]

Hematologic

• Frequency not reported: Megaloblastic anemia, sideroblastic anemia^[Ref]

Metabolic

• Frequency not reported: Folic acid deficiency, vitamin B12 deficiency^[Ref]

Dermatologic

• Frequency not reported: Rash/skin rash^[Ref]

Cardiovascular

• Frequency not reported: Congestive heart failure^[Ref]

Sudden onset of congestive heart failure occurred in patients given 1000 to 1500 mg/day.^[Ref]

Hepatic

• Frequency not reported: Elevated serum transaminases^[Ref]

Elevated serum transaminases occurred in patients with preexisting liver disease.^[Ref]

Further information

Cycloserine side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.

Medical Disclaimer