Spokane Medical Research

How much do you know about herbal medicine?

Filed under: Alternative Medicine,medicine — Rudolph @

If you’re like most doctors you could put it on a postage stamp. But like the computer herbal medicine is here to stay. Last year U.S. sales of herbal medicines reached $1.5 billion. Moreover sales are growing at 15% a year with one in 10 people using some form of “natural medication.” But what is fact and what is fiction about herbal medicine? And how dangerous are some herbs? To find out Dr. Ken Walker interviewed Dr. R. Frank Chandler director and professor of pharmacy phytochemistry and herbal remedies College of Pharmacy Dalhousie University Halifax. Dr. Ken Walker : Dr. Chandler why are more people becoming interested in herbal medicines? Dr. Frank Chandler : There are several factors. Many people have lost faith in conventional medicines or hope for a cure when traditional therapies fail. And many believe that herbal medicines are not dangerous because they’re “natural.” There’s also a fear of the more potent drugs on the market. KW : Are people fooling themselves that the word “natural” implies that herbal medicines contain some kind of magic ingredient not present in ethical pharmaceutical products? FC : There’s some belief in the herbal system that may not be well-founded. But if you look at today’s prescription medication about 25% of these drugs are either taken from plants or a plant substance that’s been modified. We wouldn’t have steroids without a couple of very lowly plants. Most of the herbal medicines have been derived through thousands of years and from different ethnic groups around the world. KW : What about the pharmacological activity of herbal medicines? FC : First of all the body can’t tell whether or not a medicine is “natural.” Pharmacological characteristics are based not on where medications are found in nature but on the activity of individual molecules. Most herbal medicines are based on real pharmacological properties. KW : How safe are herbal medicines? FC : The greatest misconception people have about herbs is that they do not perceive them as drugs. Just because it’s “natural” doesn’t imply it’s safe. The world’s greatest poisons are plants. So people must not assume that substances that come from a health food store or herbologist are safer than pharmaceutical drugs. Like prescription drugs herbs have risks and benefits that have to be weighed. After all if an herb has enough punch to cause a pharmacological reaction it also has enough to cause toxicity if taken in larger doses. So you never toy around with herbal medicines. Doctors should be particularly careful in using herbal medicines in patients suffering from chronic diseases or in pregnant women. KW : Since some herbal medicines have been around for centuries doesn’t this help to rule out toxicity? FC : This rules out acute toxicity. But it does not rule out chronic toxicity and this is a serious issue. KW : How difficult is it to detect toxicity? FC : Some types of toxicity are relatively easy to detect – for instance when the adverse effect is pharmacologically predictable and dose dependent such as muscular weakness due to hypokalemia. This may occur in those patients who are chronic users of some herbal laxatives. KW : What about the tough ones? FC : Some reactions may not be easily linked by doctors with the specific herb being taken. For example unexpected severe bronchospasm can be due to yohimbe. And hepatitis can be triggered by jin bu huan a traditional Chinese herb. KW : Any other examples? FC : Garlic has been shown to increase the effects of warfarin. Psyllium-seed products can decrease the absorption of lithium salts. Large amounts of licorice over a long term can result in hypokalemia. This in turn alters the action of drugs such as digitalis that depend on potassium levels. The use of ginseng along with monoamine oxidase inhibitors may cause insomnia and headache. And evening primrose oil may increase the risk of seizures when given with phenothiazines. So you have to be alert to the possibility of interactions between herbs and conventional medicines. Moreover the longer term risks such as carcinogenesis or teratogenesis have not been well explored. KW : Are you aware of any fatal reactions? FC : One of the worst incidents involved 48 Belgian women who attended a weight loss clinic from 1990 to 1993. They developed various degrees of renal failure from taking a Chinese herbal preparation containing Stephania tetranda Magnolia officinalis and possibly adulterants. Eighteen of these women had permanent renal failure due to fibrosing interstitial nephritis. KW : The possibility of adulterants would worry me. FC : It’s a particular problem with imported Oriental herbal remedies. For example some Oriental remedies used for arthritis have been found to be laced with dexamethasone and other steroids added to improve effectiveness! Toxic amounts of oxalates have been found in other herbal remedies. Herbal substitution is another potential danger in which more toxic herbs have been substituted for the ingredients listed on the label. KW : So quality assurance leaves a lot to be desired? FC : It’s a problem for some products. Some manufacturers have standardized the extracts of different plants. This means that when you buy the same product from one month to the next you’re getting the same strength. But for a lot of the others studies from all over the world show that this is not the case. For example if you go into a grocery store and pick up a bottle of “ginseng” about one-third of such products do not contain any of it. So quality assurance is the big issue. Moreover any medication a person takes requires specific consumer information on the label so it can be used wisely. KW : What type of information do you need for proper use of herbal medicine? FC : First the botanical name of the plant to be sure you’re getting the right plant. In some cases the specific part of the plant is critical. You need to know the dosage regimen and the amount needed for a therapeutic dose. There should be clear indication of its therapeutic uses contraindications and adverse effects where they’re known. Then a doctor pharmacist or consumer looking at the label will know how to use it wisely. KW : I’m sure doctors in spite of possible problems are going to use more herbal remedies in the future. How can they learn more about them? FC : Pharmacy schools offer programs in herbal remedies. And there are some good journals and textbooks dealing with this matter. KW : Could you provide a few herbal remedies that doctors might find useful? FC : Feverfew for migraine prevention is pretty well standardized and we have a good idea of how it works. It’s also been prescribed for dysmenorrhea and as a tonic for asthma patients. The only serious side effect is ulcers in the mouth. Another plant in which a lot of research is going on is echinacea. This herb is used to bolster the immune system and promote healing. There are some controlled studies that indicate it’s useful in treating hard-to-heal wounds. It seems to be safe but can trigger reactions in patients allergic to the daisy/chrysanthemum group of plants. KW : Anything for arthritic pains? FC : The majority of plants that are used for arthritic pain have salicylates in them. Other products have anti-inflammatory activity such as devil’s claw root. It is widely used in Europe and apparently quite successfully. In fact I’ve seen a couple of cases in Halifax where people with severe arthritis got tremendous relief from using good quality devil’s claw. KW : Do you take herbal medicines? FC : I’m cautious about all medicines. But I have taken echinacea ginseng and evening primrose oil. KW : What about the placebo effect of these herbs? FC : I think there’s a huge placebo effect with herbal medicine. But if it’s not doing you any harm and it’s having a beneficial effect it’s a fairly inexpensive way to ease the problem. KW : Who is protecting the public about herbal medicine? FC : It falls under the mandate of the Health Protection Branch. But they have not been very progressive in coming up with regulations that would protect the public. KW : Is one problem that they’re sold in health food stores as food rather than drugs? FC : Under The Food and Drug Act they’re actually in the food section and are entitled to be sold that way. But they cannot make medicinal claims or give instructions on how to use them. So you have a product out there without a label on how to use it properly. KW : Any crystal ball predictions on how herbal medicine will be used in the future? FC : There has been increasing demand from the public for these remedies everywhere outside North America. I’m sure you will see a lot more of these being used by doctors and off the counter. KW : So is Canada way behind the rest of the world? FC : I’m afraid that’s the case both in Canada and the U.S. KW : Dr. Chandler my thanks for increasing our knowledge about this subject.

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