Benzyl alcohol Use in health care

Benzyl alcohol is used as a bacteriostatic preservative at low concentration in intravenous medications. It is oxidized rapidly in healthy individuals to benzoic acid, conjugated with glycine in the liver, and excreted as hippuric acid. High concentrations can result in toxic effects including respiratory failure, vasodilation, hypotension, convulsions, and paralysis. Newborns, especially if critically ill, may not metabolize benzyl alcohol as readily as adults. Reports in the early 1980s of sixteen neonatal deaths associated with the use of saline flush solutions containing benzyl alcohol preservative led to recommendations to avoid its use in neonates.

The use of benzyl alcohol as a 5% solution has been approved by the U.S. FDA in the treatment of head lice in children older than 6 months and in adults. The product is sold in the United States (prescription-only) as Ulesfia lotion. The benzyl alcohol prevents the lice from closing their respiratory spiracles: the spiracles become blocked with the other products in the lotion, and the lice asphyxiate. The lotion is not effective against louse eggs, and so two applications with an interval of seven days are required to treat a case of louse infestation