Short-term Minoxidil Use Associated With Pericardial Effusion and Cardiac Tamponade

A 48-year-old man presented with complaints of shortness of breath and lower extremity swelling. His medical history was significant for hypertension on minoxidil and recent intracerebellar hemorrhage. Electrocardiography showed sinus tachycardia with left ventricular hypertrophy, and cardiomegaly was noted in the chest x-ray. The patient was hypertensive and tachypneic on admission. An echocardiogram taken immediately showed a large pericardial effusion with evidence of cardiac tamponade. He underwent immediate pericardiocentesis with drainage of 900 mL of pericardial fluid with significant improvement in the symptoms. Analysis of the pericardial fluid proved to be nondiagnostic. Infectious and rheumatologic causes were ruled out. After an extensive battery of tests, not yielding any diagnostic results, the pericardial effusion was attributed to minoxidil therapy. Closer monitoring is needed to prevent potentially fatal complications such as cardiac tamponade as in our patient.