Herbal medicines, adverse drug reactions

In a 5-year toxicological study of traditional remedies and food supplements carried out by the Medical Toxicology Unit at Guy s and St. Thomas Hospital, London, 1297 symptomatic enquiries by medical professionals were evaluated (28). Of these, an association was considered to have been confirmed, probable, or possible in 12, 35, and 738 cases respectively. Ten of the confirmed cases were related to Chinese or Indian herbal remedies. As a result of these findings, in October 1996 the UK Committee on Safety of Medicines extended its yellow card scheme for adverse drug reaction reporting to include unhcensed herbal remedies, which are marketed mostly as food supplements in the UK (the scheme had always apphed to hcensed herbal medicines) (29,30). This was an important milestone in herbal pharmacovigilance. 

D Arcy, P. 1991. Adverse reactions and interactions with herbal medicines. Part 1. Adverse reactions. Adverse Drug Reaction Toxicol. Rev. 10, 189-208. 

A systematic review of herbal medicines for lower back pain identified two trials of topical cayenne monopreparations and reported that adverse events in cayenne treatment groups were inflammatory contact eczema, urticaria, minute hemorrhagic spots, and vesiculation or dermatitis. In one trial, 15 adverse events were reported in the cayenne group and 9 in the placebo group (Gagnier et al. 2007). In a clinical trial of a topical capsicum plaster or placebo, localized adverse drug reactions were found in 7.5% of the patients on capsicum and 3.1% on placebo (Frerick et al. 2003). 

D Arcy PE. Adverse reactions and interactions with herbal medicines. 2. Drug interactions. 

The Constituents of Medicinal Plants was never designed as a pure exposition of chemical structures—I leave that to the analytical chemists. My belief is that the structures give us an important insight into the way herbal medicines act, and are a way of rationalising many of the traditional applications that have been passed down over the centuries. The structures also give us valuable information into the potential for adverse reactions and interactions with pharmaceutical drugs. 

As a consequence of the toxicity related to the presence of aristolochic acid in plant preparations, several health institutions, such as the US Food and Drug Administration, Therapeutic Goods Administration have recently published safety information to prevent further cases of intoxication (information available at web address http //www.cfsan.fda. gov/ dms/ds-bot.html) [471], So detecting aristolochic acids in plant species that could be used in herbal remedies, and also in herbal preparations of uncertain composition, has attracted great priority in recent years to help prevent future adverse reactions. Aristolochic acids present in medicinal plants or herbs are analyzed by soxhlet extraction followed by TLC in the Chinese pharmacopoeia [412]. Another report used multiple ultrasonic extraction followed by HPLC analysis [472]. Ong s laboratory reported a method using a home made pressurized liquid extraction (PLE) system in dynamic mode to extract aristolochic acid in medicinal plants, followed by gradient elution HPLC [473]. Several scientific communities described various analytical methods for... 

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