Minoxidil-Related Renal Function Deterioration and Pulmonary Edema: A Case Report and Literature Review

Minoxidil is a highly effective antihypertensive agent for patients with refractory hypertension. Long-term use of a high dose of minoxidil may cause several side effects. However, the concurrence of acute pulmonary edema and rapid progression of renal function after short-term and low-dose therapy is not common. Herein, we report the case of a 70-year-old woman who had diabetes mellitus and mild impairment of renal function. Low-dose minoxidil (2.5 mg) was prescribed to manage her poorly controlled blood pressure. The dosage was gradually increased to 5 mg/day. In the nineth week after the initiation of minoxidil therapy, the patient experienced weight gain (5 kg), orthopnea, and exertional dyspnea. Physical examination revealed basal crackles in both lung fields. Chest X-ray showed bilateral pleural effusions and pulmonary congestion. One week after the discontinuation of minoxidil, her body weight returned to the previous status and the symptoms of pulmonary edema subsided completely. The pleural effusion resolved gradually two weeks later. However, her renal function deteriorated rapidly and did not return to normal. This case alerts us that minoxidil should be used with caution in patients with impaired renal function. Fluid status and renal function should be closely monitored. Whenever complications develop, minoxidil should be discontinued.