Pharmacology Chemotherapy: General Principles 6cb2d3f2 Prolonged treatment with INH leads to deficiency of: A Pyridoxine B Thiamine C Pantothenic acid D Niacin High-Yield Explanation Ans. (A) Pyridoxine(Ref: Katzung 11th/e p825, KDT 8th/e p818)Isoniazid can cause peripheral neuropathy due to deficiency of pyridoxine.