Cycloserine

Cycloserine, sold under the brand name Seromycin, is a broad-spectrum antibiotic used as a second-line treatment for advanced tuberculosis and, rarely, urinary tract infections (UTIs). Specifically, it is used in conjunction with other antituberculosis medications for the treatment of active drug resistant tuberculosis. Cycloserine's use for the treatment of UTIs is similarly alternative, with the drug being primarily reserved for when conventional therapies have failed and antimicrobial susceptibility is demonstrated. It is administered orally. Cycloserine is a structural analogue of the amino acid D-alanine and works by inhibiting bacterial cell wall synthesis. As cycloserine is able to penetrate the central nervous system, it may cause side effects including headaches, drowsiness, depression, dizziness, vertigo, confusion, paresthesias, dysarthria, hyperirritability, psychosis, convulsions, and shaking (tremors). Overdose of cycloserine may result in paresis, seizures, and coma, while alcohol consumption may increase the risk of seizures. Coadministration of pyridoxine, or vitamin B6, may reduce the incidence of some CNS-related side effects. Cycloserine is not recommended for those with kidney failure, epilepsy, depression, or alcoholism. While animal studies have shown adverse effects, it is unknown if cycloserine use during pregnancy poses a developmental risk to human fetuses. Derived simultaneously by Eli Lilly and Merck from Streptomyces in 1954, Cycloserine was widely used in the 1950s and 1960s as a primary treatment for acute UTIs and tuberculosis. Upon the discovery of its neuropsychiatric side effects, usage decreased dramatically beginning in the 1970s. Cycloserine is classified as a Group B agent for the treatment of multidrug-resistant tuberculosis by the World Health Organization, a classification that defines it as a "conditionally recommended [agent] of second choice." Additionally, it is on the World Health Organization's List of Essential Medicines. Cycloserine has received some research interest from the field of psychiatry, most notably in the formulation of cycloserine/lurasidone as a treatment...