Cycloserine

Generic Name: Cycloserine
Product Name: Cycloserine

Indication

A second line agent use in the treatment of active pulmonary and extrapulmonary tuberculosis (including renal disease). It should be used when the offending organisms are susceptible to cycloserine, and treatment with primary medications (streptomycin, isoniazid, rifampicin, ethambutol) has failed. Cycloserine is best used in combination with other anti-tuberculous agents rather than as a sole treatment.

Cycloserine may also be used in the treatment of urinary tract infections caused by susceptible micro-organisms. However it is rarely more effective than conventional antimicrobials, other than mycobacteria.

Action

Microbiology.

Cycloserine inhibits cell wall synthesis in susceptible strains of Gram positive and Gram negative bacteria, and in M.tuberculosis.

Pharmacology.

Cycloserine has a low therapeutic index. Toxicity is usually associated with blood levels > 30 mg/L. Administration should be discontinued or the dosage reduced if the patient shows signs or symptoms of allergic dermatitis, or CNS toxicity.

Dose advice

Adults: 500 mg â?? 1 g daily, in divided doses. E.g. 250 mg every 12 hours for 2 weeks. Daily dosages should not exceed 1 g

Children: 10 mg/kg/day. Adjust according to blood levels and therapeutic response.

Elderly. Dosage should be reduced in the presence of impaired renal function.

Use in pregnancy. Cycloserine crosses the placenta, however the effect of cycloserine on the fetus is not known. It should only be administered to pregnant women if clearly indicated.

Use in lactation. Cycloserine is excreted in breast milk, therefore lactating women should either discontinue the drug or discontinue breast feeding.