1. A 67-year-old black man with a history of glucose-6-phosphate dehydrogenase (G-6-PD) deficiency presents with fever, irritative voiding symptoms, and perineal pain. Rectal examination is remarkable for a boggy, exquisitely tender prostate. A urine Gram's stain is positive for gram-negative rods. The risk for development of hemolytic anemia is highest if he receives high-dose, 21-day therapy with