Pharmacy-based computer system for monitoring and reporting drug interactions

A pharmacy-based computer system for monitoring and reporting drug interactions is described, and physicians' responses to patient management suggestions generated by the system are reported. Using information from a commercially available drug-interaction database, a pharmacist chose 41 potentially interacting drug combinations to include in the pharmacy's automated system. A warning notice appears on the computer screen if one of these drug combinations is prescribed. Pharmacists who encounter these notices while entering medication orders telephone the prescribing physician if the combination represents a Class I interaction (immediate onset, major severity, established documentation); for Class II interactions, which have a delayed onset, a copy of the warning notice and suggestions for patient management are placed in the prescribing physician's mailbox. The system was evaluated during a three-month period in 1985 to determine physicians' responses to the patient management suggestions. A total of 927 patients had 1004 potentially interacting drug combinations prescribed for them. Changes in drug dosage were made in 44% of these instances, and in 75%, patients were monitored for the development of adverse clinical effects. A computerized drug-interaction monitoring system can help increase physicians' awareness of possibly interacting drug combinations and provide them with useful information about the clinical management of patients for whom such drug combinations have been prescribed.