The intention of this article is not to discourage the use of complementary therapy, but rather to supply some food for thought when contemplating decisions about these remedies. The companies that promote herbs, supplements and vitamins advertise the potential benefits of the products but the consumer has very little information about the products themselves -- their true value for treating specific conditions or even information about the actual content of the products they are buying. Promoters of supplements and herbs are often the first to criticize prescription drugs as the products of "big business," but supplements and herbs are themselves part of a huge industry with annual sales of around $20 billion. This article will highlight emerging concerns about the use of various complementary approaches and also address ways to minimize potential risks associated with the use of these therapies, where possible.
People should be aware of these things and take measures to reduce their risk of buying contaminated products or products without active ingredients by seeking out reputable sellers of herbs, vitamins and supplements. Seek guidance from a trained alternative medicine practicioner (e.g., an herbalist or nutritionist who specializes in HIV) and gather information about the products you are considering using. Taking the word of people selling the product in stores is no guarantee of accuracy. On the actual package, or on their websites, some manufacturers of herbs and supplements will claim that their products have been tested for active ingredients. Do a little research and see what you can learn. For example, some consumer publications, such as Consumer Reports and other similar groups like consumerlab.com, periodically test supplements and list what is actually in various brands. Even this, however, doesn't tell you whether the product will benefit you. As a general rule of thumb, if a company has shown integrity in some of its products that have been tested by consumer groups, it is a reasonable sign that they maintain similar standards for other products in their line. According to researchers who are evaluating these therapies, the quality products that undergo evaluation by the manufacturer are in general not the ones that you'll find at your average grocery store or pharmacy.
Part of what led researchers to look at St. John's Wort for potential interactions with anti-HIV therapy is that the herb is processed in the body by the same enzyme used for processing many drugs, including protease inhibitors and most NNRTIs. This enzyme is called the p450 enzyme. A number of dietary supplements and herbs have reported effects on the p450 enzyme. Depending on how they interact with p450, using anti-HIV therapies with these products could lower the blood levels of the anti-HIV therapies (possibly putting people at risk for developing resistance to their anti-HIV drugs) or they could increase the blood levels of the anti-HIV therapies (putting people at greater risk for serious side effects). Herbs with reported effects on the p450 enzyme include:
Dr. Piscitelli of the National Institutes of Health (NIH) is championing a series of interaction studies to provide people with HIV information to enhance the safe use of complementary therapies with anti-HIV medication. In a recent presentation, Piscitelli noted that the most common supplement used by people attending the NIH's HIV clinic is garlic. Piscitelli will evaluate this in future studies. A woman recently initiated a ritonavir (Norvir)-containing anti-HIV regimen and then began garlic supplementation. After starting the garlic, she developed severe nausea and vomiting which resolved after she stopped the garlic. It may be that garlic increased the levels of ritonavir, and thus its side effects. There has also been a second report where it appears garlic supplementation may have enhanced the side effects associated with ritonavir. Garlic may also increase the risk of side effects associated with other anti-HIV therapies. This information, coupled with knowledge that garlic has a reported effect on p450, suggests that until more is known people should use caution when combining high doses of garlic with anti-HIV therapies that use the p450 pathway (e.g., protease inhibitors and NNRTIs). Moreover, people using the supplement with anti-HIV drugs who experience serious stomach problems (diarrhea, nausea or vomiting) might consider discontinuing it to see if these symptoms lessen.
According to a recent article in the medical journal The Lancet, there are a number of reported herb-drug interactions that include the following herbs:
To lessen the likelihood of herb-drug interactions, Dr. Piscitelli encourages people to have more in-depth discussions about the use of complementary therapy with their doctors and pharmacists. This may take some getting used to for both patients and doctors. Doctors may need to learn to listen and support their patients, in a nonjudgmental way, about the use of complementary therapy. Undoubtedly it may well be patients who drive this learning curve. Patients need to be open and honest about what they are using and considering. The only way to capture information about drug interactions and side effects is if they are recorded in a complete drug history, including herbs, vitamins and supplements that you are using. It's also important for patients, doctors and pharmacists to keep up on the latest information about drug-herb interaction studies.
The following is a list of herbs with known serious side effects:
Liver toxicity, light sensitivity
Heart failure, stroke, hypertension
Inflammation of the liver (hepatitis)
Below is a list of vitamins with known side effects.
|Vitamin||Potential Side Effects of Supplementation|
|Vitamin A and beta-carotene||Perhaps the most toxic vitamin. At high doses (greater than 25,000 IU per day) toxicities are more likely, including loss of appetite, weight loss, bone malformations, spontaneous fractures, internal bleeding, liver toxicities and birth defects.|
|Vitamin B-6 (pyridoxine)||Reversible neuropathy has been reported in people taking high doses (500mg to 6 grams a day) over extended periods of time.|
|Vitamin B-12||In very rare instances, allergic reactions have been reported.|
|Folate||High doses have been associated with reduced zinc absorption.|
|Vitamin C||High doses can cause diarrhea and gastrointestinal distress. Buffered formulations are available and may decrease stomach problems. People with a history of kidney stones should consult a physician before taking high doses.|
|Vitamin D||Potentially very toxic; can cause bone lesions. Toxicities reported with single high dose supplementation.|
|Thiamin||Very high intravenous doses have caused intoxication, headache, convulsions, muscular weakness, paralysis and cardiac arrhythmias.|
|Biotin||No reported toxicities.|
|Vitamin E||No reported toxicities.|
|Riboflavin||No reported toxicities.|
|Pantothenic Acid||No reported toxicities in humans.|
|Vitamin K||No reported toxicities in humans.|
|Niacin||Toxicites may be related to formulation. Nicotinic acid can cause itching, nausea, vasodilation and vomiting at doses of 2 to 4 grams/day. Nicotinamide only rarely produces these toxicities.|
Unlike pharmaceutical products, large studies are not required to document side effects associated with complementary therapy and potential side effects are typically not noted on the package materials. The key to minimizing the risk of potential side effects with these therapies is to learn about them, monitor for early signs and implement measures to minimize the risk.
There are numerous herbal remedies that contain controlled and potentially dangerous substances that are banned by the FDA. The FDA readily admits that it simply doesn't have the enforcement potential to ensure that these products stay off the shelves of some stores. Media exposés on this topic in California reveal countless tales of people harmed by such products that contain lead, arsenic, anabolic steroids and other controlled and potentially dangerous substances.
To protect yourself, seek reputable sellers, investigate the product and seek guidance from trained professionals.
In the United States alone, it's estimated that $20 billion dollars were spent on complementary therapies last year. The use of complementary therapies has risen almost 400% in the past eight years and it's estimated that 50% of people in the U.S. use complementary therapies. The sale of complementary products is an ever growing industry and at the current time that industry has done very little to document the safe and effective use of its products. It's unlikely that it ever will. The U.S. Government, through the NIH, has established two botanical centers to evaluate complementary and alternative therapies with a budget of $68 million dollars. A third center will be funded shortly. Every few years, new discussions are held about whether and how to better regulate the marketing of nutritional supplements and herbs.
There is a great difficulty in evaluating herbs and herb-drug interactions because often times the active ingredient of the products and its dose are not known. Moreover, drug interaction studies for pharmaceutical products typically take a matter of a week to ten days. Drug-herb interaction studies are expected to take much longer, and as a consequence be more expensive, as it's likely that people will have to be taking herbs for a matter of weeks before an effect is seen. Even when the interactions are determined for one particular product, it is unclear how they will relate to other similar products because of the lack of control over dosing. Because no studies have determined the appropriate or best dose of many complementary therapies, researchers face an additional challenge in first selecting the dose of herbs to use in studies. Necessary funding for the studies will remain a problem and limitation to moving forward rapidly. Many companies selling herbal and other complementary approaches are reluctant to fund studies that may reveal that their products are not useful, have side effects or have interactions with commonly used medications. This information could hurt their "bottom line" of profit. Pharmaceutical companies are also unwilling to fund these studies for many of the same reasons, and the FDA does not require them.
Whatever the possible benefits of herbs, vitamins and supplements, there simply is no information to guide decision-making with regard to using these remedies. Be aware that using them entails some element of risk.
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