An individual with isoniazid (INH) toxicity may present with which symptoms?

Isoniazid (INH) is a medication primarily used to treat tuberculosis, but it can lead to toxicity, particularly when overdose occurs or when it interacts with other medications. One of the notable effects of isoniazid toxicity involves its impact on the peripheral nervous system. The symptoms of tingling and numbness are indicative of peripheral neuropathy, which can result from isoniazid's interference with vitamin B6 (pyridoxine) metabolism. INH can lead to a deficiency in this vitamin, and this deficiency is responsible for the development of neuropathic symptoms, such as tingling and numbness in the extremities.

Recognizing these specific symptoms is crucial because they can indicate that the patient is experiencing serious side effects due to INH. Addressing peripheral neuropathy early can involve supplementing with vitamin B6 to alleviate these symptoms, thereby preventing further complications. The presence of these distinct neurological signs makes this choice the most fitting symptom pattern associated with isoniazid toxicity.