A 25-year-old woman presents to her gynecologist with complaints of a recurrent vaginal discharge accompanied by burning and pruritus. Physical examination reveals vaginal erythema and edema. Direct microscopic examination of vaginal secretions in 10% KOH reveals yeast cells. You diagnose her with vulvovaginal candidiasis and prescribe fluconazole. The patient asks you about the main adverse effects of this medication. Which of the following is the most likely major side effect associated with fluconazole?
