Monitoring the Safety of Herbal Medicine
Herbal medicines are used extensively in the general population, often in patients with chronic illnesses who are at high risk of adverse events (AEs).
In the UK, there is a spontaneous reporting scheme specifically for medical herbalists to report suspected adverse herbal reactions (AHR), in conjunction with the Yellow Card scheme. However, the limitations of such schemes are well known. The DSRU is investigating the feasibility of developing an active surveillance system, based on Prescription Event Monitoring (PEM), to monitor the safety of herbal medicines, dispensed to patients by herbalist practitioners, using Hypericum perforatum (St John’s Wort) as the model herb (because of known risks of selected AHRs).
The objectives are to develop a systematic process for monitoring the safety of herbal medicines prescribed by herbalists and to identify and quantify AEs associated with the study herb. The proposed methodology will use an observational cohort design. As for PEM, exposure data will come from herbalists’ records of new prescriptions containing H. perforatum and outcome data will come from health events recorded by herbalists on simple questionnaires sent out six months after starting treatment. Event data will be analysed in an identical manner to standard PEM studies. This methodology could be further developed to monitor the safety of proprietary herbal preparations.