Reserpine, a root extract of the naturally occurring plant Rauwolfia serpentina, was used in the past as a first-line therapy for reducing blood pressure. Nowadays, it is used less commonly as a second-line treatment. This review aimed to assess reserpine's efficacy as a first-line agent in reducing blood pressure in primary hypertension. The method involved finding and summarising the best existing evidence from randomised controlled trials. We considered the quality of the included studies to be reasonable, with acceptable randomisation and blinding methods overall, as shown in the 'Risk of bias' graphs. We noted a weakness when the studies did not provide a detailed description of the methods or results, thus, introducing potential reporting bias arising from selective reporting or other biases, such as lack of concealment of allocation. To ensure we include only good-quality evidence, we only rated a study highly if there was clear evidence that all efforts had been made to ensure neither the participant nor the clinician or assessors were aware of what drug the participant was taking, through concealment of allocation and blinding throughout the study.

This systematic meta-analysis concluded that reserpine is effective in reducing systolic blood pressure as a first-line agent. The degree of this effect was mild to moderate. Because the four included studies did not investigate a wide range of doses, no data were available to infer a dose-related response in blood pressure. Insufficient data were available to evaluate the adverse effects of reserpine therapy. This update did not reveal new studies; as such, the conclusions of this review remain unchanged and represent the most up-to-date evidence, current to October 2016.