A nurse is caring for a client who receives lamotrigine daily for bipolar disorder and reports a rash on his arm. Which of the following actions should the nurse take?

The correct answer is C: Withhold the next dose of the medication. This is the correct action because lamotrigine can cause a serious skin reaction called Stevens-Johnson Syndrome or Toxic Epidermal Necrolysis. Any rash should be evaluated promptly, and the medication should be stopped if a rash occurs. Applying hydrocortisone cream (choice A) may not address the underlying cause and can potentially worsen the condition. Asking about laundry detergent (choice B) is not relevant in this situation. Explaining that the medication causes a temporary rash (choice D) is inaccurate and may delay appropriate action.