A 54-year-old man comes to the hospital due to 4 days of progressive nasal congestion, facial pain, swelling, and fever. The patient has taken over-the-counter decongestants, which provided no relief. He has a history of uncontrolled diabetes mellitus due to dietary and medication noncompliance. The patient's temperature is 38.3 C (101 F). Examination shows right facial swelling and purulent nasal discharge with necrotic destruction of the nasal mucosa and turbinates. The diagnosis of invasive mucormycosis is made, and surgical debridement is performed. He is started on an antifungal agent that binds to ergosterol and alters cell membrane permeability. Considering the adverse effects of this medication, which of the following should be routinely monitored in this patient?

Question

A 54-year-old man comes to the hospital due to 4 days of progressive nasal congestion, facial pain, swelling, and fever.  The patient has taken over-the-counter decongestants, which provided no relief.  He has a history of uncontrolled diabetes mellitus due to dietary and medication noncompliance.  The patient's temperature is 38.3 C (101 F).  Examination shows right facial swelling and purulent nasal discharge with necrotic destruction of the nasal mucosa and turbinates.  The diagnosis of invasive mucormycosis is made, and surgical debridement is performed.  He is started on an antifungal agent that binds to ergosterol and alters cell membrane permeability.  Considering the adverse effects of this medication, which of the following should be routinely monitored in this patient?

Quizplus · Accepted Answer

Mucormycosis should generally be treated with antifungal therapy and surgical debridement. Amphotericin B is the initial drug of choice. It binds ergosterol in fungal cell membranes to form holes. Resultant changes in membrane permeability lead to cell death. Renal toxicity is the most notorious side effect of amphotericin B. The drug causes renal vasoconstriction and a reduction in the glomerular filtration rate. It may also act as a direct toxin on renal epithelial cells, leading to acute tubular necrosis, renal tubular acidosis, and electrolyte disturbances. Severe hypokalemia and hypomagnesemia (likely reflecting increased distal tubular membrane permeability) can occur, with most patients requiring supplementation. Renal injury may also lead to decreased erythropoietin production and produce a normochromic normocytic anemia. Patients with mucormycosis who respond to initial amphotericin therapy may be switched to posaconazole. Liver function test monitoring is recommended in patients taking azoles. (Choice A) Examples of drugs that can cause isolated thrombocytopenia include heparin, beta-lactam antibiotics, and vancomycin. (Choice B) Bisphosphonates (used for osteoporosis) affect bone metabolism and can cause hypocalcemia. Foscarnet (used for treating ganciclovir-resistant cytomegalovirus infections) also causes hypocalcemia. (Choice C) Daptomycin can induce rhabdomyolysis, leading to elevated creatine phosphokinase. (Choice E) TSH monitoring is recommended for patients taking amiodarone (used for treating arrhythmias) or lithium (used for treating bipolar disorder). Educational objective: Amphotericin B is a polyene antifungal drug notorious for its renal toxicity. Severe hypokalemia and hypomagnesemia are commonly seen during therapy and often require daily supplementation.

A 54-Year-Old Man Comes to the Hospital Due to 4