Cycloserine is a second-line anti-TB antibiotic, a D-alanine analogue that acts by inhibiting mycobacterial cell wall synthesis. It is used in multidrug-resistant tuberculosis (MDR-TB) treatment regimens.
Also known as: Seromycin, ácido cicloserino
Antituberculous + antituberculous: additive CNS toxicity.
Both can cause seizures and psychiatric disturbances. Additive effect on neurological toxicity.
Seizures, psychosis, dizziness.
Seizures, psychosis.
Monitor neurological and psychiatric function.
DailyMed/FDA; EMC-EMC PT
Food does not significantly affect cycloserine absorption.
Can be taken with or without food.
DailyMed/FDA (NIH/NLM) — approved Cycloserine label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=8e7e2665-7a3d-3f54-9f92-5fe845f02ef9
Cycloserine may lower the seizure threshold. Patients with epilepsy are at increased risk.
Avoid in patients with uncontrolled epilepsy. Use the lowest possible dose.
DailyMed/FDA (NIH/NLM) — approved Cycloserine label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=8e7e2665-7a3d-3f54-9f92-5fe845f02ef9
Animal studies demonstrated CNS effects. Limited human data. Use only when benefit outweighs risk.
Avoid in 1st trimester. Use in 2nd/3rd trimesters only for severe MDR-TB.
Unknown if excreted in breast milk. Artificial feeding is recommended.
Reliable contraception is recommended.
DailyMed/FDA (NIH/NLM) — approved Cycloserine label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=8e7e2665-7a3d-3f54-9f92-5fe845f02ef9
Clinical and educational support tool. The information does not replace a medical prescription or the opinion of a qualified healthcare professional.
Cycloserine inhibits D-alanine-D-alanine ligase, an enzyme essential for mycobacterial cell wall peptidoglycan synthesis.
Structural analogue of D-alanine — competes with the natural substrate of D-alanine-D-alanine ligase, blocking peptidoglycan synthesis.
Oral bioavailability: ~70-90%. Tmax: 3-4 hours. Rapid and nearly complete absorption.
Minimally metabolised — ~65% excreted unchanged in urine. Secondary hepatic metabolism.
8-12 hours. Renal elimination: 65% unchanged. Adjust dose in renal impairment.
Medicines from the same therapeutic group (ATC classification) or the same pharmacological class.
