Which of the following is a side effect of Isoniazid?

Isoniazid, a first-line medication used to treat tuberculosis, is known to have specific side effects that can affect liver function and vitamin levels in the body. One of the most significant side effects is hepatotoxicity, which refers to liver damage that can occur with its use. This toxicity can lead to elevated liver enzymes and, in severe cases, liver failure.

Additionally, isoniazid can cause a deficiency in pyridoxine, also known as vitamin B6. This deficiency occurs because isoniazid can interfere with the metabolism of vitamin B6, which is essential for various biochemical processes, including the synthesis of neurotransmitters. Symptoms of pyridoxine deficiency may include peripheral neuropathy, which manifests as numbness or tingling in the extremities.

While nausea and vomiting, headaches, and diarrhea can occur with many medications, including isoniazid, the hepatotoxicity and pyridoxine deficiency are particularly notable and specific to the drug. Understanding these potential side effects is critical for monitoring patients on isoniazid and providing appropriate interventions when necessary.