Vitamins, supplements and herbs have long been used by people with HIV in hopes of helping manage side effects of other therapies and/or improve overall general health.  Unfortunately, not many approaches have been studied in people with HIV or been looked at to see how they might interact with commonly used medications, or whether they add to the overall benefits of therapy.

The intention of this article is not to discourage the use of vitamins, supplements and herbs, but rather to supply some food for thought when contemplating decisions about these remedies. 

A Little Background …
Under current law, vitamins, supplements and herbs do not have to be evaluated by any regulatory agency prior to their sale. All they need do is assert that the product is "generally regarded as safe." What this means is that there is no requirement for studies to demonstrate the effectiveness and safety of these products—leaving the consumer with little or no meaningful information about benefits or side effects of therapy. Some manufacturers vaguely reference "studies" in their promotional literature, but these are seldom more than very small, uncontrolled studies. Also, these products do not have to be manufactured in accordance with the rigid guidelines established for the manufacturing of pharmaceutical products, called Good Manufacturing Practices. As a consequence, there is extremely wide variability between products in terms of their active ingredients, and even between batches of the same product from a single manufacturer. In fact, studies have shown that some of the products being sold on the market today contain no amount of the claimed active ingredients, whatsoever. Other products being sold as herbal supplements have been shown to contain dangerous chemicals (e.g. arsenic and lead, both potentially deadly). Still other products have been shown to actually contain pharmaceutical medications. The best manufacturers, however, make a serious effort to deliver the real product in the amounts claimed, but due to the lack of regulatory requirements, there is no simple way to determine who is telling the truth.

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 practitioner (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.

Drug Interactions
St. John's Wort, a popular over-the-counter herbal supplement (also known as hypericin) used for mild depression, has been shown to have potentially serious interactions with protease inhibitors and non-nucleoside reverse transcriptase inhibitors (NNRTIs).  This doesn't mean that St. John's Wort doesn't "work" for helping people deal with depression, but rather it poses a serious drug interaction problem that could jeopardize the effectiveness of anti-HIV therapy.

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:

• St. John's Wort
• Garlic
• Ginseng
• Melatonin
• Milk Thistle (silymarin)
• Geniposide
• Skullcap

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. 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 (diarrhoea, 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 non-judgmental way, about the use of complementary therapy.  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.

What About Side Effects?
The biggest myth about complementary therapies is that they are non-toxic. There is a widely held misconception that because something is natural, or sold over-the-counter, that it doesn't have side effects. To the contrary, there have been numerous reported cases of people with HIV experiencing side effects from complementary therapy. Chinese herb preparations that contain deer antler, for example, can cause nausea, diarrhoea and other kinds of stomach upset.  High doses of vitamin C can cause severe diarrhoea. Taking too many B vitamins can lead to a complication that lands one in the hospital and excessive levels of vitamin A can be highly toxic to the liver. Side effects associated with herbs, vitamins and supplements might not reveal themselves immediately. It may take a number of weeks after starting a therapy for side effects to emerge as a problem. Keeping an accurate record of every therapy you are taking, including when you start and stop therapies and documenting the onset of side effects may help to sort out which therapy is causing the problem.

The following is a list of herbs with known serious side effects:

Below is a list of vitamins with known side effects.

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.

Buyer Beware!
To protect yourself, seek reputable sellers, investigate the product and seek guidance from trained professionals.