PATIENT COMPLIANCE AND THERAPEUTIC COVERAGE - AMLODIPINE VERSUS NIFEDIPINE (SLOW-RELEASE) IN THE TREATMENT OF ANGINA-PECTORIS

Patient compliance with therapy is often poor and overestimated by the treating physician; it is particularly important in cardiovascular di seases such as hypertension and angina pectoris. Compliance was studie d in an open parallel study in out-patients with stable angina pectori s, given either amlodipine (5 mg, once daily) or slow-release nifedipi ne (20 mg, twice daily) for 12 weeks. Compliance was assessed using pi ll counting and using an electronic device, the medication event monit oring system, to record the time and date of each opening and closure of the pill container. There was no difference between the two groups in pill count or in 'taking compliance' (the percentage of prescribed doses taken as indicated by the monitoring system). Compliance was sig nificantly better (P < 0.001) with amlodipine, however, for 'correct d osing' (the percentage of days on which the correct dose was taken) an d for 'timing compliance' (the percentage of doses taken at the prescr ibed time interval after the last dose). 'Therapeutic coverage' (the e stimated proportion of treatment time for which the drug was active) w as also significantly better for amlodipine (P < 0.001). There was no difference in reported side-effects between the two therapies.