A 4-year-old boy is hospitalized on the pediatric service with cough, runny nose, and chest pressure. Concern for respiratory syncytial virus is brought up by the treating physician. Treatment with zanamivir is undertaken. Which of the following underlying conditions can worsen bronchospasm in this patient?

A 4-year-old boy is hospitalized on the pediatric service with cough, runny nose, and chest pressure. Concern for respiratory syncytial virus is brought up by the treating physician. Treatment with zanamivir is undertaken. Which of the following underlying conditions can worsen bronchospasm in this patient?

A 45-year-old man with HIV disease and herpesvirus has begun on therapy with foscarnet. The medication is administered intravenously. If serum electrolytes are drawn on this patient after 1 week of therapy, which of the following laboratory values would be expected to be abnormal?

A 43-year-old man with leukemia is hospitalized for treatment after his prior chemotherapeutic regimen failed to produce remission. Bone marrow biopsy is repeated and indicates the presence of hairy cell leukemia. Treatment with fludarabine has begun. This agent likely works in which of the following ways?

A 63-year-old woman presents with a productive cough, shortness of breath, and fever and chills. Past medical history is significant for chronic renal disease. After a standard dose of which of the following drugs would you expect to see the greatest increase in serum drug concentration?

An 18-year-old female plans to take a mission trip to Ghana for 2 weeks during the summer following her senior year of high school. Her doctor recommends starting a regimen of mefloquine before her trip for malaria prophylaxis rather than the traditional chloroquine because of widespread resistance to chloroquine. What is the mechanism of chloroquine resistance?