The administration of over-the-counter medications to infants and small children is widespread, occasionally leading to life-threatening toxic effects. Classic examples are acetaminophen and aspirin. We present the case of a 4½-week-old male infant who had a 24-hour history of decreased responsiveness ultimately shown to be due to hypermagnesemia.
The patient had been carried to term (birth weight, 3.04 kg), and was born to a primiparous healthy white woman following an uncomplicated pregnancy. He was discharged home at 2 days of age and did well until 3 weeks of age when he developed otitis media. He completed a 10-day course of amoxicillin 2 days prior to admission. His parents are second cousins. This infant had 2 maternal cousins with congenital heart disease. One of these infants died at 4 months of age and the other had a ventricular septal defect.
Sullivan JE, Berman BW. Hypermagnesemia With Lethargy and Hypotonia Due to Administration of Magnesium Hydroxide to a 4-Week-Old Infant. Arch Pediatr Adolesc Med. 2000;154(12):1272-1274. doi: