We report a case of isoniazid induced convulsions in 35 years old male alcoholic and smoker patient receiving intensive phase therapy for pulmonary tuberculosis. A case was confirmed by accidental positive de-challenge and rechallenge as well as ruled out other conditions. Use of isoniazid in alcoholic and smoker patient required a caution for prevention of neurological adverse reactions. Pyridoxine should always be prescribed to such patients for the prevention of such adverse reaction.
Keywords: Adverse drug reaction, alcohol, convulsions, isoniazid, pyridoxine deficiency, smoking.