Recent study on safety monitoring herbal medicines of Thai National Essential Drug List (NEDL)

To promote the use of herbal medicines in hospitals, 8 single formulations were added into the Thai NEDL. There are Curcuma longa, Zingiber officinale, Cassia alata, Andrographis paniculata, Centella asiatica, Clinacanthus nutans, Capsicum frutescens and Zingiber purpureum. As with other modern medicines, herbal medicines should be governed by standards of safety monitoring that are equivalent to those required for modern medicines. Thai FDA issued the notification on safety monitoring herbal medicines within 2 years. In the meantime, the HVC has conducted a project: Intensive safety monitoring on herbal medicines of Thai NEDL. Objective: To investigate and categorize adverse events (AEs) of herbal medicines mentioned above. Duration of this project is two years, from 2007–2009. Method: Prospective study by intensive monitoring all patients who took herbal medicines in hospitals which were enrolled in the study. The patients were interviewed by pharmacists and structured questions form was given to them asked for followed up 2 times by telephone or come back. All reports were analyzed. Results: A herbal using reports were 2,335 times during the study period (Oct 1, 2007-Jan 31, 2009). Of these, 59% were Curcuma longa, 30% were Andrographis paniculata and 11% were the rest of 8 formulations. All 54 AEs occurred and they were assessed by WHO algorithm. Thirty six (67%) reports of Curcuma longa AEs were collected. Of these, 61% were gastrointestinal system disorders: nausea, abdominal pain, flatulence, anorexia, diarrhea, etc. Thirty three percents were general disorders including chest discomfort, headache, dizziness etc. Seventeen percents of AEs reports were Andrographis paniculata: abdominal pain, anorexia, inflammations. Conclusion: Almost all AEs occurred from using herbal medicines were known but for using among large populations, we should be continuing efforts to monitor safety, to assure and promote using them based on scientific evidenced.