Read the acyclovir Results-at-a-Glance summary.

Herpes simplex virus (HSV) is a dangerous infection that can often cause death or mental disability in infants. Acyclovir is a medicine approved by the U.S. Food and Drug Administration (FDA) for HSV but the best and safest dose of acyclovir for infants, particularly premature infants, was not previously known. The “Open-Label Study to Describe the Pharmacokinetics of Acyclovir in Premature Infants” study was conducted in order to learn more about the appropriate level of acyclovir dosing for infants.