A nurse is assessing a client who is taking furosemide for heart failure. Which of the following findings indicates an adverse effect of the medication?

Furosemide is a loop diuretic that can cause ototoxicity, manifesting as hearing loss, tinnitus, or vertigo. This adverse effect is particularly associated with high doses or rapid IV administration and is more common in clients with renal impairment. Hearing loss is a well-documented and serious adverse effect of furosemide that should be reported to the provider and monitored closely. Increased blood pressure is not an adverse effect of furosemide; in fact, the medication is used to reduce fluid overload and lower blood pressure, so hypertension would suggest the medication is not working effectively rather than representing a drug adverse effect. Ankle edema is actually the symptom furosemide is prescribed to treat in heart failure, so its presence suggests treatment ineffectiveness rather than an adverse drug reaction. Decreased blood sugar is not a typical adverse effect of furosemide; if anything, furosemide has been associated with hyperglycemia due to potassium depletion impairing insulin secretion, not hypoglycemia. Hearing loss therefore stands as the correct adverse effect attributable to furosemide therapy.