<prompt> Side effects of isoniazid are all EXCEPT ?HepatitisOptic neuritisPeripheral NeuropathyThrombocytopenia  <response>: Ans. is d i.e., Thrombocytopenia Adverse effects of INH -Peripheral neuritis most common, hepatitis, optic neuritis atrophy, seizure, ataxia, muscle twitching, toxic encephalopathy, psychoses, rashes, fever, ahralgia, acne, lupus like syndrome, hemolytic anemia in G6PD deficiency. Note: Most common antitubercular drug which is implicated in causing peripheral neuropathy is INH. 