Possible Interaction: Cycloserine and Vitamin B 6

“Antituberculotic drugs such as INH and cycloserine interfere with vitamin B6 metabolism and may produce a secondary niacin deficiency.”

“Our purpose in this was twofold-to determine the effectiveness of cycloserine in doses of 2 grams per day in the treatment of resistant pulmonary tuberculosis, and to discover if the dentral nervous system damage caused by cycloserine could be prevented by the use of pyridoxine.”

“It is considered that cycloserine inhibits the vitamin B6-enzyme system in bacteria by forming a complex with vitamin B6.”

“Under similar incubation conditions, the entry of labeled APL and of PLP into the myelin membranes in the presence of L‐cycloserine decreased markedly (50%) in comparison to controls.”

“Mechanism-based inhibitors such as cycloserine and gabaculine can inactivate aminotransferases via reactions of the compounds with the pyridoxal phosphate cofactor forming an irreversible adduct.”

“The substantial change in fluorescence intensity at 450 mµ that follows the reaction of cycloserine with pyridoxal 5-phosphate was used to monitor the release of the cofactor from the active site of the enzyme glutamate aspartate transaminase.”

“ D-Cycloserine , an antibiotic produced by different strains of Streptomyces, to which frequent side effects on the central nervous system—particularly seizures and psychotic reactions—are attributed, inhibits the pyridoxal-5-phosphate dependent enzymes L-glutamic acid- and L-dopadecarboxylase in vitro.”

“3.The … of CS has been reduced, a)… the concomitant administration of pyridoxine hydrochloride , which also protects against INH in combination therapy; b)by spreading the daily dose as widely as possible, and c)by insuring that the plasma levels of CS are kept well below 50 mcg./ml.”