A 32-year-old G2P1 woman in her third trimester presents to the ambulatory care clinic with dysuria and urgency. Urine is nitrite positive and leukocyte esterase positive. A drug commonly used to treat urinary tract infections is trimethoprim-sulfamethoxazole, but the physician is reluctant to use it. What risk is the physician worried about?

A 32-year-old G2P1 woman in her third trimester presents to the ambulatory care clinic with dysuria and urgency. Urine is nitrite positive and leukocyte esterase positive. A drug commonly used to treat urinary tract infections is trimethoprim-sulfamethoxazole, but the physician is reluctant to use it. What risk is the physician worried about?

A 43-year-old woman who is obese undergoes laparoscopic cholecystectomy following repeated episodes of right upper quadrant pain caused by cholelithiasis. Over the next 48 h, she is found to have an MRSA wound infection. Her physician administers daptomycin. Which of the following laboratory values should she follow most closely as a result of daptomycin administration?

A 34-year-old immigrant with HIV disease complains of a productive cough with hemoptysis and night sweats. A sputum smear is positive for acid-fast bacilli. He is placed in isolation and started on isoniazid, rifampin, pyrazinamide, and ethambutol. A few months later, he complains of a loss of his ability to discriminate certain colors. What is causing his vision impairment?

A 48-year-old man who is obese and a chronic alcoholic is hospitalized for spontaneous peritonitis. He begins a course of gentamicin as part of an empiric antibiotic regimen. Which of the following medications should the physician avoid prescribing while this patient is taking gentamicin?

A 27-year-old man hospitalized following a kidney transplant develops a high fever, tachycardia, and hypotension. Blood cultures grow Candida albicans. He is started on amphotericin B and flucytosine. Which of the following describes part of flucytosine’s mechanism of action?