Inhibits cell-wall biosynthesis by interfering with the bacterial use of amino acids. Action may be bacteriostatic or bactcricidal, depending on the concentration of drug attained at the site of infection and tile susceptibility of the infecting organism.
INDICATIONS & DOSAGE
Adjunctive treatment in pulmonary or extrapulmonary tuberculosis -
Adults: initially, 250 mg P.O. q 12 hours for 2 weeks; then, if blood levels are below 25 to 30 mcg/ml and no toxicity has developed, dose is increased to 250 mg q 8 hours for 2 weeks. If optimum blood levels are still not achieved and no toxicity has developed, then dose is increased to 250 mg q 6 hours. Maximum dose is I g/day. If CNS toxicity occurs, drug is discontinued for 1 week, then resumed at 250 mg daily for 2 weeks. If no serious toxic effects occur, dose is increased by 250-mg increments q 10 days until blood level of 25 to 30 mcg/ml is obtained.
Children: 10 to 20 mg/kg/day P.O. in two divided doses (maximum of 0.75 to I g).
Acute urinary tract infectiolls -
Adults: 250 mg P.O. q 12 hours for 2 weeks.
ADVERSE REACTIONS
CNS: seizures, drowsiness, somnolence, headache, tremor, dysarthria, vertigo, confusion, loss of memory, possible suicidal tendencies, psychosis, hyperirritability, paresthesia, paresis, hyperreflexia, coma.
Contraindicated in patients hypersensitive to drug and in those with seizure disorders, depression or severe anxiety, psychosis, and severc renal insufficicncy. Also contraindicated in patients who usc alcohol excessivcly.
SPECIAL CONSIDERATIONS
Use cautiously in patients with impaired renal function: reduced dose is rcquircd.
A specimen for culture and sensitivity tests should be obtained before therapy begins and periodically thereaftcr to detect possible rcsistance.
Cycloscrine is considered a "secondline" drug in the treatment of tuberculosis and should always be administered with other antituberculotics to prevent the development of resistant organisms.
Serum cycloserine levels must be monitored periodically, especially in patients receiving high doses (over 500 mg dai ly) because toxic reactions may occur with blood levels above 30 mcglml.
Hcmatologic tests and renal and liver function studies must be monitored.
Patient should be watchcd for psychotic symptoms, hallucinations, and possible suicidal tendencies.
Pyridoxine, an anticonvulsant, tranquilizer, or sedative may be given to relieve adverse reactions.
Patient teaching
Avoid alcohol, which may cause serious neurologic reactions.
Do not perform hazardous activities if drowsiness occurs.
Report adverse reactions promptly because dosage adjustment may be necessary or other medications may be prescribed to relieve adverse reactions
