[A case of minoxidil intoxication].

A 26-year-old man was found unable to move after oral consumption of 120 mL of RiUP X5® (containing 5 g/100 mL minoxidil) as a suicidal attempt. The patient complaining of frequent vomiting and weakness was transferred to our hospital. Findings on arrival: GCS E4V5M6; respiratory rate 24/ min; blood pressure 83/43 mmHg; pulse 152/min, regular; SpO₂97% (oxygen by mask: 6 L/min); thus, the patient was in shock. The systolic blood pressure and the pulse rate improved to about 90 mmHg and to about 130/min, respectively, in response to rapid intravenous infusion of 2,000 mL of lactated Ringer's solution. His circulatory condition tended to improve with parenteral fluid infusion alone. Forty hours after admission, however, heart failure developed due to excessive I.V. fluid infusion and abnormal body fluid distribution associated with delayed vascular smooth muscle relaxation; therefore, mechanical ventilation was initiated. Simultaneously, intravenous noradrenaline infusion was started because of a fall of the blood pressure. Subsequently, as the patient's respiratory and circulatory conditions gradually improved, he was weaned from mechanical ventilation, and the noradrenaline infusion was discontinued at 108 hours after admission. The patient made favorable progress and was discharged home on the 9th hospital day. Minoxidil exerts adverse effects mainly on the cardiovascular system. Since minoxidil is an over-the-counter drug readily available to the public, and emergency physicians should be aware of its severe toxicity.