What condition is a client likely experiencing if they report numbness and tingling in the extremities after taking isoniazid (INH) for 2 months?

The client is likely experiencing peripheral neuritis due to the effects of isoniazid (INH), which can cause deficiency in vitamin B6 (pyridoxine). This medication is commonly used to treat tuberculosis, and its neurotoxic effects may lead to symptoms such as numbness and tingling in the extremities, reflecting damage to peripheral nerves.

Isoniazid interferes with the metabolism of neurotransmitters and the synthesis of hemoglobin, contributing to a condition where there is insufficient vitamin B6, which is crucial for nerve health. Signs of peripheral neuritis often include sensory symptoms, such as tingling or numbness, particularly in the hands and feet, as nerves in these areas are affected.

The other conditions listed would not typically present with the specific symptoms reported by the client. Hypercalcemia usually leads to different symptoms such as weakness or confusion, small blood vessel spasm may cause pain or coldness in extremities, and impaired peripheral circulation is often associated with other underlying cardiovascular issues. Thus, the most fitting interpretation of the client’s symptoms is peripheral neuritis, as this aligns directly with the side effects associated with isoniazid therapy.