Playing it safe with complementary medicines
Posted on 30th November, 2011
Some 15 years ago, a Chinese herb, artemisinin, was identified as a possible treatment for malaria. Previously quinine, known as the bitter principle in tonic water, was one of the most widely used antimalarial treatments; and was the drug of choice well into the 1940s. Quinine occurs naturally in the bark of the cinchona tree, the medicinal properties of which were known in South America by at least the 17th century.
In the mid 1700s, based on a similar bitter taste of its bark, the English Willow tree was also supposed to provide health benefits. Later it was discovered that salicylic acid gave willow bark this bitter taste, and although salicylic acid is far too toxic to be taken orally (it’s still used for removing corns and warts), it gave rise to what some medical scientists call the 20th century wonder drug – aspirin.
Clearly, herbal medicines are often effective, sometime potent, but not always necessarily safe (quinine, until quite recently also used to treat nocturnal cramps is now never recommended for this condition because of possible serious adverse effects). Still, many of today’s pharmaceutically synthesised products have been developed from their herbal ancestors.
Nowadays, products marketed as medicinal herbs, where the active ingredients haven’t been isolated and purified, are generally categorised as CAMs – complementary and alternative medicines. The term complementary medicine covers a wide range of products and therapies. As well as herbal preparations, these include vitamins, minerals and other nutritional supplements, some aromatherapy products and homeopathic treatments.
A distinction can be made between complementary and alternative treatments, where the former are used together with the “conventional” therapy and the latter instead of. Many people prefer complementary medicines because of the perception they are safe even though they might be less potent and less effective than so-called scheduled products. But, natural is not necessarily safe. And in either case, with complementary or alternative medicines, there is the potential for problems to occur.
Scheduled products, whether they be prescription medicines or non-prescription pharmacy only medicines, are required to be evaluated by the Therapeutic Goods Administration (TGA) for quality, safety and efficacy. Indeed, any product which claims to be a cure or to be able to manage, treat or prevent a disease must also undergo similar evaluation. So, we can generally be confident that such medicines will do what they’re meant to do.
For the so-called complementary medicines, it is somewhat more difficult getting accurate and objective information.
Most complementary medicines, considered to be of comparatively low risk, are simply “listed” with the TGA. This generally ensures they are manufactured appropriately with safe ingredients, but these listed medicines are not evaluated for efficacy, so the TGA does not guarantee they work; whereas, the “registered” prescription and most non-prescription medicines which are available only in pharmacies must meet levels of quality and safety and be demonstrated to be effective.
Aust L numbers (for listed medicines) and Aust R numbers (for registered medicines) must appear on the product labels.
It’s important to understand that CAMs contain chemicals like any medicine and can have adverse side effects and interactions like any medicine - sometimes more so. (Homeopathic “medicines” are an exception. They contain no active ingredients and work simply as, sometimes expensive, placebos). So, if CAMs are your cup of herbal tea, check with your pharmacist or doctor first, especially if you are taking any other medicine.
High Wycombe Pharmacy has a fact card titled Complementary Medicines. The card identifies the problems and pitfalls of CAMs, and also indicates which of the claims made for various popular CAMs can be supported by evidence.
Published by the Pharmaceutical Society of Australia and written by John Bell