Which antituberculous drug requires vitamin B6 supplementation if dietary intake is insufficient?

Isoniazid is the antituberculous drug that requires vitamin B6 (pyridoxine) supplementation when dietary intake is insufficient. This is because isoniazid can interfere with the metabolism of pyridoxine in the body, potentially leading to a deficiency. Vitamin B6 is essential for various neurological functions and for the synthesis of neurotransmitters. A deficiency in vitamin B6 can result in neurological side effects, such as peripheral neuropathy, which is a common concern among patients taking isoniazid.

By supplementing with vitamin B6, the risk of these neurological adverse effects can be reduced, maintaining safer treatment for the patient. This precaution aligns with the management strategies for patients undergoing treatment for tuberculosis with isoniazid, especially if their dietary intake is inadequate or if they have other risk factors for vitamin B6 deficiency.