Ingestion of minoxidil associated with elevated transaminases in the absence of ischemic hepatitis

Minoxidil is a direct-acting vasodilator that induces relaxation of the vascular endothelium, and historically, it has been used as an antihypertensive agent. It caused hypertrichosis, resulting in its typical use today as an alopecia treatment. Toxicity is characterized by hypotension and tachycardia, often requiring treatment with α-adrenergic agonists. A previously healthy 18-year-old woman presented to the emergency department three hours after ingesting 60 mL of 5% W/V topical minoxidil solution. Initial vitals included sinus tachycardia at 117 beats per minute and a blood pressure of 92/44 mmHg. Laboratory analyses performed three hours post-ingestion revealed elevated aspartate and alanine aminotransferases (224 and 384 IU/L, respectively). Acetaminophen and ethanol concentrations were undetectable. Isotonic crystalloid, N-acetylcysteine, phenylephrine, and midodrine were administered. She developed pulmonary edema, requiring diuresis and supplemental oxygen via a nasal cannula. She was discharged 108 hours post-ingestion after a full recovery. Minoxidil toxicity may be an uncommon etiology of abnormal transaminase concentrations.