Evaluation of an antihypertensive therapy utilising meta-analysis of a clinical trial database

The emphasis on evidence-based medicine and the use of safe, cost-effective therapeutic strategies demands that management decisions be based upon evidence derived from clinical studies. Whilst prospective double blind clinical trials are regarded as the gold standard, there is no doubt that meta-analysis has proved valuable in defining the benefits of antihypertensive therapy. The antihypertensive efficacy of lacidipine has been assessed in a retrospective meta-analysis of a series of clinical studies in which the drug was compared with placebo and all the major classes of antihypertensive agent. All of the studies entered into the meta-analysis were parallel group double blind trials. Efficacy was based upon the reduction in both systolic and diastolic blood pressure and the effect on heart rate at trough immediately prior to dosing during maintenance therapy. In placebo controlled trials a clear dose response relationship was apparent with blood pressure reductions that were significantly greater than that observed with placebo at doses of 2 mg lacidipine and above. In active control trials, diastolic blood pressure reductions of 10-15 mmHg were observed at the end of the monotreatment phases (> 6-8 weeks) with a final reduction of 15-20 mmHg with the efficacy of lacidipine being equivalent to that of the comparator drug. Comparable results were also achieved for the response rates to therapy which varied between 70 and 85% at the end of the monotreatment phase and 82-98 when combination with other antihypertensive agents was permitted. There was no evidence of cardio-acceleration in any of the trials where significant blood pressure reduction was detected. This retrospective analysis in a large population base confirms the documented antihypertensive efficacy of lacidipine and demonstrates the suitability of the drug as a first line antihypertensive agent.