ObjectiveTo describe the use of computer technology to enhance our ability to identify and notify providers of potential drug therapy problems using a mail intervention monitoring programme.SettingPharmacy benefit management company.InterventionUse of clinical software systems and professional support to help physicians and pharmacists eliminate drug therapy problems using a drug therapy problem notification service. The service begins with an automated clinical screening system. Pharmacists then review the potential problems for relevance. After a potential problem is identified, the system generates letters to physicians and pharmacists. The letters describe the problem and explain its significance, provide recommended alternatives and supporting references, and give a patient prescription profile. Key enhancements to the system included:use of a commercially available personal computer database program;client-server connections to large data sources;creation of sophisticated computer screening criteria;on-screen patient drug therapy problem review;system loading of patient, physician and pharmacy information;automated follow-up; andcriteria modification based on therapy changes.Main outcome measures and resultsFrom January 1998 through July 1999, the service notified physicians and pharmacists of 100 894 potential problems for 49 892 patients. Over 60% of the interventions resulted in a change of drug therapy. Without this system it took over 3 months to mail letters. The turnaround time now takes less than 15 days. Pharmacists can now review 14 times as many potential problems in the same amount of time as taken previously.ConclusionA combination of end-user programme development and information services department support considerably reduced the time required to identify, and notify providers about, potential drug problems compared with our previous system.