Q. A 35-year-old female presents to the emergency department complaining of milky discharge from her breasts. She reports that the discharge started about 2 weeks ago and has been progressively getting worse. She denies any pain or tenderness in her breasts. Her menstrual cycles have been regular and she denies any recent changes to her menstrual cycle. She also denied any previous history of breast disease or surgery. On physical examination, her vital signs are within normal limits. Breast examination reveals milky discharge from both nipples without any palpable masses or tenderness. The rest of her physical examination is unremarkable. Laboratory workup is done and her serum prolactin level is found to be significantly elevated. You order a pituitary MRI to evaluate for the presence of a pituitary adenoma, which is negative. Before starting her on treatment with a dopamine agonist to lower her prolactin levels, you review her list of current home medications. Which of the following medications is the LEAST likely cause of her symptoms?