Supplements and Drugs: A Hazardous Combination

As I have become more involved in using functional nutritional therapy in my practice, I have come to realize that many people are still confused about the safety and effectiveness of various dietary supplements. Because these products are “natural”, many feel they are always safe to use. Although supplements and herbs can be safer than pharmaceutical drugs, they can still function as drugs in the body and should be used with caution and respect.

It is estimated that over 80% of the world’s population and 60 million Americans use some form of complementary and alternative medicine CAM. However, although many believe CAM compliments their current traditional healthcare, most do not inform their physicians that they are taking these products. And, many providers don’t ask or discuss CAM use with their patients, although one survey of 181 cardiologists found that half of them took antioxidant vitamins, themselves.

What many people don’t realize is that there is no regulatory agency in charge of the supplement industry. Herbal products are not tested for purity, effectiveness and safety as drugs are. In 1994, the Dietary Supplement Health and Education Act DSHEA was enacted that requires the FDA to prove beyond any doubt that a supplement is unsafe before removing it from the market. Other than regulating what can be included on the label, they are unable to enforce any other regulation.

There is no incentive for supplement companies to conduct research because they are unable to patent ‘natural’ products. Those marketing herbs and other supplements save millions of dollars not spent on research, or worse, yet, conduct their own “research”, which often does not include rigorous controls. Although there are many excellent and reputable supplement companies on the market, the typical consumer is unlikely to know who the credible ones are. Many independent sales representatives only know what the company tells them, and are as unaware as the consumer.

Even if the supplements are pure and not harmful by themselves, problems arise when combined with drugs. Dietary supplements may compete with drugs, leading to toxicity or treatment failure of that drug. An estimated 4 million people are at risk for herbal-prescription drug interactions. Here is a list of the most common interactions between supplements and drugs:

• Warfarin Coumadin is used to prevent blood clotting for those at risk for deep vein thrombosis, stroke, or heart attack. Supplements that can change bleeding time controlled by this drug include flaxseed oil and fish oil supplements, goldenseal, saw palmetto, feverfew, garlic, ginseng, and willow bark, just to name a few.

• Digoxin is another heart medication. Ginseng has been noted to falsely elevate blood digoxin levels. Some herbs that will affect drug effectiveness include senna, licorice, aloe, cascara, hawthorne, foxglove, goldenseal and guar gum.

• Phenytoin is a drug used for seizures. Herbal interactions to be aware of include ginkgo biloba, white willow, lemon balm, skull cap, kava kava, and valerian root, to name a few. It is also important to know that Folate supplementation is necessary with Phenytoin, but excess Folate can be harmful.

• It’s important to take calcium supplements and vitamin D two hours apart from taking either Phenytoin or Digoxin in order to not interfere with these drug’s effects.

  Of particular concern are interactions with the herb St. John’s Wort, which is taken by 7.5 million Americans as a depression remedy. This herb can cause serious consequences when taken with drugs such as Prozac, Zoloft, or Paxil, as well as warfarin, cyclosporine, and oral contraceptives. This herb may also interact with Digoxin, chemotherapy drugs, and other drugs, causing treatment failure. Some of these interactions are serious enough that if St. John’s Wort were a drug, the government would restrict marketing, make it a prescription-only item, or require label warnings.

So, what can one do

Anyone taking a dietary supplement should first do their homework. Know exactly what the purpose of a particular supplement is for and learn all known interactions. There are many excellent informational websites on the internet. A good rule of thumb is to look for a site that does not offer products for sale!

It’s also important to inform your healthcare professional what supplements you are taking, in order to avoid potential supplement-drug interactions that could put you at medical risk. Although many credible professionals sell products, there are just as many who sell products but don’t really understand the physiology of the human body and are just out to make money. Supplement sales is a very popular ‘easy’ way to make money today!

It’s just as important to do one’s homework when looking for a complementary care practitioner. Although this is only one set of criteria, the best recommendation is to look for one or any of these: A pharmacist or registered dietitian who is educated in medicinal herbs, a physician who specializes in functional medicine, or an MD, OD, ND, DC, PharmD or RD who also has the CCN credential.

Don’t be afraid to take supplements. They serve a very beneficial purpose. But do know why you’re taking each supplement, just as you should know why you take any prescription medications. Be an informed consumer and take responsibility for your health and wellbeing.