A patient taking isoniazid is concerned about adverse effects. Which of the following would be a common adverse reaction?

A patient taking isoniazid is concerned about adverse effects. Which of the following would be a common adverse reaction?

• A. Hair loss
• B. Nausea
• C. Jaundice
• D. Rash

Answer: (C)

Isoniazid can cause hepatotoxicity, and liver injury from this drug often shows up as jaundice due to impaired bilirubin processing and hepatitis. This is a well-recognized, clinically important adverse effect that clinicians monitor for during therapy, especially in people who are older, drink alcohol, have preexisting liver disease, or take other hepatotoxic drugs. That’s why jaundice is the best choice here: it directly signals liver injury from isoniazid. Hair loss is not a typical or common reaction to isoniazid. Nausea and rash can occur, but jaundice reflects a more characteristic and potentially serious toxicity. If jaundice develops, the drug should be stopped and medical evaluation sought, with liver function tests monitored and precautions like avoiding alcohol discussed.

Isoniazid can cause hepatotoxicity, and liver injury from this drug often shows up as jaundice due to impaired bilirubin processing and hepatitis. This is a well-recognized, clinically important adverse effect that clinicians monitor for during therapy, especially in people who are older, drink alcohol, have preexisting liver disease, or take other hepatotoxic drugs. That’s why jaundice is the best choice here: it directly signals liver injury from isoniazid.

Hair loss is not a typical or common reaction to isoniazid. Nausea and rash can occur, but jaundice reflects a more characteristic and potentially serious toxicity. If jaundice develops, the drug should be stopped and medical evaluation sought, with liver function tests monitored and precautions like avoiding alcohol discussed.