A comparison of the use, effectiveness and safety of bezafibrate, gemfibrozil and simvastatin in normal clinical practice using the New Zealand Intensive Medicines Monitoring Programme (IMMP)

Aims Because of the importance of treating dyslipidaemia in the prevention of ischaemic heart disease and because patient selection criteria and outcomes in clinical trials do not necessarily reflect what happens in normal clinical practice, we compared outcomes from bezafibrate, gemfibrozil and simvastatin therapy under conditions of normal use. Methods A random sample of 200 patients was selected from the New Zealand Intensive Medicines Monitoring Programme's (IMMP) patient cohorts for each drug Questionnaires sent to prescribers requested information on indications, risk factors for ischaemic heart disease, lipid profiles with changes during treatment and reasons for stopping therapy. Results 80% of prescribers replied and 83% of these contained useful information. The three groups were similar for age, sex and geographical region, but significantly more patients on bezafibrate had diabetes and/or hypertension than those on gemfibrozil or simvastatin. After treatment and taking the initial measure into account, the changes in serum lipid values were consistent with those generally observed, but with gemfibrozil being significantly less effective than expected. More patients (15.8%) stopped gemfibrozil because of an inadequate response compared with bezafibrate (5.4%) and simvastatin (1.6%). Gemfibrozil treatment was also withdrawn significantly more frequently due to a possible adverse reaction compared with the other two drugs. Conclusions In normal clinical practice in New Zealand gemfibrozil appears less effective and more frequently causes adverse effects leading to withdrawal of treatment than either bezafibrate or simvastatin.