Final answer:
An indication of an adverse reaction to amphotericin B, an antifungal medication, is decreased potassium levels. This is a result of the medication's nephrotoxic effects, which include renal potassium wasting and subsequent hypokalemia.
Step-by-step explanation:
A nurse evaluating a client receiving amphotericin B via intermittent IV bolus should be aware of the medication's potential adverse reactions. One of the findings that indicates an adverse reaction to this medication is decreased potassium levels. Amphotericin B can cause several side effects, and nephrotoxicity is a common severe side effect that can result in renal potassium wasting, leading to hypokalemia. While a slight increase in urine output could potentially occur with amphotericin B, it is not necessarily indicative of an adverse reaction, as long as electrolyte balance is maintained. Hypertension is not directly related to amphotericin B use, and contact dermatitis or a diffuse rash, while possible, is more commonly related to other causes such as allergy or infection.