Levels of acetyl hydrazines and rate of acetylation of isoniazid in adult tuberculosis patients.

Patients suffering from pulmonary tuberculosis were investigated for the levels of isoniazid (INH) and its metabolites viz. acetyl-INH, mono and diacetyl hydrazines and ammonia. It was observed that 50% of the patients are slow inactivators of INH and almost all show an increase in circulating levels of NH3 at 6 hrs. Mono and diacetyl hydrazine levels in blood and urine were detectable in all the patients up+o 24 hrs though the maximum levels were observed at different intervals after the intake of INH.