Which of the following are serious side effects of gabapentin?

• A. Weight gain and edema with reduced urine output
• B. Cough
• C. Fever, body aches, swollen glands, and flu-like symptoms
• D. Nausea

Answer: (C)

Gabapentin can cause a range of side effects, but signs like fever, body aches, swollen glands, and flu-like symptoms can indicate a serious reaction that needs prompt evaluation. This combination can reflect a systemic hypersensitivity or serum sickness–like reaction to the medication, meaning the immune system is reacting in a way that can affect multiple parts of the body. Because of this potential danger, these symptoms warrant stopping the drug and contacting a clinician right away, or seeking urgent care if they appear, especially if a rash, trouble breathing, or facial swelling develop.

Less alarming symptoms like nausea or cough are common and usually milder; they may be bothersome but don’t on their own signal a dangerous reaction.