Abstract
Recently, drug administration to patients has been complicated both qualitatively and quantitatively, and many hazards owing to drug interactions and individual differences in drug metabolism have been reported. Therefore, accurate and full information on drug metabolism should be accumulated for each patient. Effect of concurrent drug administration on aminopyrine metabolism in patients with chronic diseases (pulmonary tuberculosis etc.) was studied. Rate of aminopyrine demethylation was depressed in the patients. The depression was hardly affected by suspending drug administration for 24 hours. This indicates that the diminished capacity may be due to repression rather than to inhibition of the drug-metabolizing enzymes. However, rate of acetylation of aminopyrine metabolites was not depressed in patients. In volunteers of low acetylation, administration of pantethine increased acetylation of aminoantipyrine and concurrent administration of isonicotinic acid hydrazide and aminopyrine decreased the acetylation. Taking alcohol beverages inhibited production of 4-formylaminoantipyrine, one of the metabolites of aminopyrine.
