Which of the following are potential side effects of acyclovir?

• A. N/V, diarrhea, headache; rare confusion, hallucinations, kidney injury
• B. Drowsiness only
• C. Hair loss
• D. Increased appetite

Answer: (A)

Acyclovir tends to cause GI upset and headaches, and it can also lead to rare but serious CNS effects (confusion, hallucinations) and kidney injury, especially with IV use or inadequate hydration. The option that lists nausea, vomiting, diarrhea, and headache along with rare confusion, hallucinations, and kidney injury best captures both the common and the more serious, less frequent adverse effects. Other choices miss these important effects or focus on symptoms not typically associated with acyclovir (such as hair loss or increased appetite), or they are far too limited (like drowsiness only).