Captopril: 4 years of post marketing surveillance of all patients in New Zealand.

The Intensive Medicines Monitoring Programme (IMP), a specialised part of the New Zealand Post Marketing Surveillance system, has been used to monitor captopril since it was first approved for marketing for the treatment of hypertension and heart failure. Monitoring has consisted of (1) spontaneous reporting for which doctors have been encouraged to report all clinical events, (2) a specific event recording survey at the end of the first year and (3) a controlled patient survey of taste disturbance. The IMP gathers prescription information on about 85% of all patients. There were 4,124 patients at the end of the first 4 years. Reported events involved 4% of patients, the majority being cutaneous (1%) and gastrointestinal (0.7%). The event recording survey gave an overall rate of adverse events of 2.2 per patient year. The taste survey showed a remarkably high incidence of taste disturbance in the control population and only taste loss was significantly higher (P less than 0.01) for captopril. This ongoing study has so far demonstrated a low incidence of adverse effects due to captopril, which is reassuring in view of its increasing use for mild hypertension and early cardiac failure.