The recent editorial by Holden and Joseph on interactions between herbal remedies and antirheumatic drugs Citation[1] highlights one area of a widespread and growing problem of the compatibility of self-prescribed herbal remedies and those prescribed through the conventional healthcare system.
The two main issues are that of communication between patient and health practitioner, as well as the availability and reliability of safety data on these issues. The new EU regulations regarding the herbal medicine directive came into force in the UK on the 31st October 2005; this should improve the quality of these products on our pharmacy/health store shelves but does not address the above problems. Both matters are of grave concern and are not unrelated. It is only through patient awareness of the importance of informing the GP/consultant about herbal remedies they are taking and in turn the practitioner including relevant questions during consultations that we are going to compile accurate and useful information concerning drug–herb interactions via the yellow card system.
If we can produce quality data on the safety of herbal remedies and their potential for drug interactions, it will also hopefully help to eliminate inaccurate and in some cases unnecessary alarmist reports across various media with certain herbal remedies. An example of which came up in the Holden and Joseph editorial. They are not alone in reporting an association of black cohosh (Actaea racemosa) with hepatotoxcity. To my knowledge, this conclusion has been made on the strength of three case reports of hepatic adverse events. Two of these cases involved multiple herbal preparation with no causality determined Citation[2,3]. The third case has suggested a link between an unknown (quality or content) monopreparation of black cohosh and autoimmune hepatitis with further analysis of this case throwing doubt on this link Citation[2,4]. Thus, the association of black cohosh and hepatoxicity is speculative and helps neither patient nor practitioner.
Therefore, in conclusion, we want to get the message across about the seriousness of herb–drug interactions, but we want it to be the right message so that the decision to both take herbal remedies and to advise on such, can be an informed one.
Alyson Huntley, Universities of Exeter & Plymouth, UK
Author’s response
We thank the author for her helpful comments and agree that open and honest communication between doctors and patients about the use of herbal remedies is essential if an accurate database on adverse effects and drug interactions is to be compiled. We disagree, however, about her statement that the association of black cohosh and hepatotoxicity is speculative. Whilst causality has not been established conclusively in one cited case Citation[3], it is strongly suggested in that of another patient who developed symptoms and signs of hepatotoxicity a week after taking black cohosh alone Citation[2]. Previous criticism of this case has suggested that the exact composition of the preparation was unknown Citation[5]. This does not mean that black cohosh was innocent, however, and merely emphasises the statements made in our editorial that many herbal remedies are of poor quality and reliability and that all suspected adverse events should, therefore, be reported Citation[1]. Further cases linking black cohosh and hepatotoxicity have also been described Citation[6] including one of fulminant liver failure Citation[7].
Space in our editorial did not permit us to mention that although there are few reports of hepatotoxicity associated with black cohosh, following the citation of these reports in October 2004 Citation[8], the Medicines and Healthcare Regulatory agency as of March 31st 2005 had received a further 20 reports of suspected liver reactions ranging from abnormal liver function tests to hepatitis Citation[101].
The long-term safety of black cohosh has not been established. Patients with inflammatory arthritis often use medication such as black cohosh for many years rather than for the short-term relief of menopausal symptoms. Whilst we agree that accurate reporting of adverse effects is essential, the evidence that black cohosh may be associated with hepatotoxicity continues to mount and we, therefore, do not consider our opinions to be either speculative or unnecessarily alarmist.
Wendy Holden, Swindon & Marlborough NHS Trust, UK
Bibliography
- HOLDEN W, JOSEPH J: Interactions between herbal remedies and antirheumatic drugs. Expert Opin. Drug Saf. (2005) 4(6):969-974.
- WHITING PW, CLOUSTON A, KERLIN P: Black cohosh and other herbal remedies associated with acute hepatitis. Med. J. Aust (2002) 177(8):432-435.
- LONTOS S, JONES RM, ANGUS PW, GOW PJ: Acute liver failure associated with the use of herbal preparations containing black cohosh. Med. J. Aust (2003) 179(7):390-391.
- THOMSEN M, SCHMIDT M: Hepatotoxicity from Cimicifuga racemosa? Recent Australian case report not sufficiently substantiated. J. Altern. Complement. Med. (2003) 9(3):337-340.
- VITETTA L, THOMSEN M, SALI A: Black cohosh and other herbal remedies associated with acute hepatitis. Med. J. Aust. (2003) 178(8):411-412.
- COHEN SM, O’CONNOR AM, HART J, MEREL NH, TE HS: Autoimmune hepatitis associated with the use of black cohosh: a case study. Menopause (2004) 11(5):575-577.
- LEVITSKY J, ALLI TA, WISECARVER J, SORRELL MF: Fulminant liver failure associated with the use of black cohosh. Dig. Dis. Sci. (2005) 50(3):538-539.
- MCA/CSM: Current problems in pharmacovigilance. (2004) 30:11.
Website
- http://www.mhra.gov.uk/home/idcplg?IdcService=SS_GET_PAGE&useSecondary=true&ssDocName=CON1004342&ssTargetNodeId=663 MHRA website. Black cohosh.