[Minoxidil intoxication, the pharmacological agent of a hair lotion]. / Intoxication par le minoxidil, principe actif d'une lotion capillaire. À propos d'un cas.

Accidental intoxications in children are frequent but most of them are without serious consequences. We describe herein the case of a young girl who drank 100 mg of a topical hair lotion with minoxidil. On arrival, she had no symptoms except flush on the face and ears. Four and half hours after ingestion, tachycardia appeared with a pulse above 170 beats per min with hypotension at 76/24 mmHg. The heart rate remained between 170 and 190 beats per min for 12 h and then lowered to between 140 and 160 beats per min. Thirty-six hours after ingestion, the heart beat was at 140 beats per min. Minoxidil is a strong vasodilator used first in the 1970s for severe hypertension. It produces hypotension by direct arteriolar vasodilatation. Only a few cases of minoxidil intoxication have been described in the literature, including only one pediatric case. This young boy had only tachycardia of 160 beats per min for 40 h. Most serious cases have been described in adults. They suffered long-lasting tachycardia, hypotension, and ECG changes. Most patients need a bolus of normal saline fluid and some with hemodynamic problems need vasoactive drugs such as dopamine and/or phenylephrine. All patients need to be under medical supervision for a long time because of the product's very long action.