In the article on varicella-zoster infections in the January issue (Pediatr Rev. 2008;29:5–11), the oral dose of acyclovir for children is given as 20 mg/kg qid. To clarify, the dose is 20 mg/kg per dose qid. The dose recommended in the article for adolescents is 4,000 mg/day and is based on the treatment for adults who have zoster. The American Academy of Pediatrics Red Book (27th ed. 2006:785) cites a dose of 800 mg qid (3,200 mg/day) for adolescents, and the author of the article in the January issue recommends using that dose, although there should be no significant clinical difference between the two regimens. Acyclovir is available in 800-mg tablets. Patients at serious risk for or who have severe or potentially severe infections should be treated with intravenous acyclovir.