A 70 year old insulin-dependent patient has just completed a 7 day course of ampicillin for a respiratory infection. He presents with signs and symptoms consistent with a diagnosis of oral candidiasis. Which of the following is the most appropriate management for this patient?

Prescribe nystatin.

Prescribe clindamycin.

Prescribe a topical steroid.

Reduce the patient’s insulin dose.

Double the patient’s insulin dose.