What symptom is important for a nurse to watch for in a client taking isoniazid?

In clients taking isoniazid, monitoring for numbness and tingling is essential due to the risk of peripheral neuropathy, a potential side effect of the medication. Isoniazid can interfere with the metabolism of vitamin B6 (pyridoxine), leading to deficiencies that may manifest as nerve-related symptoms, such as numbness or tingling in the extremities. This is especially important for clients who have pre-existing conditions that could predispose them to neuropathy or those who may require isoniazid for an extended period.

Recognizing these symptoms early allows the nurse to intervene appropriately, which may include assessing the patient's vitamin B6 levels and possibly administering vitamin B6 supplementation to help alleviate these side effects. This proactive approach can help prevent more severe neurological complications associated with vitamin deficiencies in clients receiving isoniazid therapy.