Utilization and safety of oral acyclovir over an 8-year period

The primary purpose of this project was to develop and implement surveillance systems to monitor the short- and long-term safety of acyclovir in oral dosage forms in a general population, the Kaiser Permanente Northwest (KPNW) region membership. KPNW is a group model HMO providing comprehensive care to over 390,000 members located primarily in the Portland, Oregon-Vancouver, Washington metropolitan area. Data were collected from the automated outpatient prescription, hospital discharge, tumor registry, KPNW membership information, and from medical record reviews, over an 8-year period. The findings showed oral acyclovir use increased substantially, and females were twice as likely to receive oral acyclovir as males. Most use was short-term. When the hospitalizations of oral acyclovir users with select serious morbidities conditions were examined following the receipt of acyclovir, no temporal association was observed between exposure to oral acyclovir and the hospitalizations. Similarly, where oral acyclovir was being used within a time frame possibly associated with serious life-threatening conditions, other morbidities rather than acyclovir were the likely cause of the condition, and no mention was made in the medical record that acyclovir might have been involved in the condition. In summary, oral acyclovir was a safe drug within the use patterns of the HMO population over an 8-year period.