<prompt> ATT drug causing hyperuricemia:IsoniazidPyrazinamideStreptomycinRifampicin  <response>: Ans. b PyrazinamideRef : KDT 6th ed. 742Pyrazinamidemicrosomal deaminase---pyrazinoic acidPOAxanthine oxidase---5-hydroxypyrazinoic acid Pyrazinamide is hydrolyzed by microsomal deaminase to pyrazinoic acid POA and then hydroxylated to 5-hydroxypyrazinoic acid by xanthine oxidase for excretion by the kidneys. Pyrazinamide is a first line antitubercular drug that can cause hyperuricemia secondary to inhibition of uric acid secretion in the kidney and hepatotoxicity. This hyperuricemia leads to arthralgia due to competitive inhibition of xanthine oxidase by POA. It should not be stopped if hyperuricemia develops Ethambutol also produces hyperuricemia due to interferance with urate excretion. 