Reactions between supplements and prescription drugs
Are there supplements that interfere with your prescription drugs?
The very short answer is no because it is extremely rare than any supplement could exert an effect on a prescription drug. The reason that supplements and prescription drugs do not interfere is that your body handles them in their own separate ways.
When you swallow a supplement, in most cases it will contain minerals, vitamins, antioxidants, amino acids or herbs that may or may not have been edible. Since your body is accustomed to breaking down food into these components, it recognizes supplements as just another food source and digests them as if you were eating a meal. Minerals, vitamins, amino acids, antioxidants and even an item like glucosamine which is extracted from chicken cartilage are all initially broken down by your saliva and stomach acid which accounts for 10 per cent of their absorption. Then after your stomach empties, your digestive enzymes break down the rest and send all the different components to areas of the body where they are needed.
Prescriptions drugs are treated in a totally different fashion. When your body swallows these medications it does not recognize them at all and in order to protect you sends them immediately to your liver for detoxification. However, prescription drugs are designed for just such an occasion. This means that when the liver starts the process of detoxifying a prescription drug it actually creates an active metabolite that is then released into your blood stream to possibly lower your blood pressure, lower your cholesterol or perhaps to keep your heart rate lower. Every drug has what is known as a half-life. This means that after so many hours only one half of the drug remains in your bloodstream. At this point your body returns this drug to your liver for detoxification on the assumption that it is finished and ready to be taken out of your body. However once again when the liver detoxifies the drug it is converted to another metabolite and goes out into your bloodstream to do its work.
Every time a prescription drug goes through your liver, scientists call it a liver-pass. The drug Vioxx that may have killed 28,000 people had seven liver passes and this extra strain on the liver along with all the drugs used in combination with Vioxx caused many people to have heart attacks and strokes.
The most difficult drug for your body to detoxify through your liver is Coumadin (warfarin) and most people on this drug also take a multitude of other drugs. Because warfarin takes so long to pass through your liver, the other drugs sometimes stay in your bloodstream too long and the patient winds up with a higher dose of each drug which can cause many problems. So the reality is that almost every prescription drug interferes with almost any other prescription drug and it is almost laughable that many doctors blame interactions on supplements.
Another example of the way your body treats prescription drugs occurs if you are undergoing chemotherapy for some type of cancer. These drugs are so powerful they have the potential to kill every cell in your body. When they are swallowed or injected, your body under normal circumstances would register a huge immune system response and send out killer white cells to destroy the invader. That is why patients on chemotherapy have to take prednisone, a drug that completely supresses your immune system so the chemotherapy drugs can do their work.
There are some really rare cases in which supplements interfere with prescription drugs and one example is the herb St. Johns Wort. It passes through a part of your liver known as cytochrome p-450, a liver enzyme that usually acts on prescription drugs. For this reason it acts like a prescription drug and slows down the detoxification of other drugs leading to higher doses in your blood stream.
Sometimes interactions may occur if the effect of the supplement is similar to the effect of the prescription drug. Many people take antidepressant drugs and they inhibit the uptake of serotonin and in some cases norepinephrine in your brain. Supplements like Tryptophan, 5-HTP and St.John’s wort could interfere with action of the antidepressant. Even the new diet pill, green coffee bean extract exerts an effect on norepinephrine and therefore is contraindicated if the dieter is taking an antidepressant. Many people buy Korean red or American ginseng for energy or for Type 2 diabetes without realizing that it can cause an increase in heart rate and increase your blood pressure. This means it is contraindicated in any person with Type 2 diabetes and any person with high blood pressure or a person with any type of heart condition.
Do Any Herbal Supplements Thin Your Blood?
The short answer to this question is actually, no. I find it very disturbing that many of the so-called experts who write health books have virtually no knowledge of the biochemistry of the human body and thus have no idea of its complexity. They usually wrongfully conclude that if a substance increases blood flow then it must do so by thinning the blood. This could not be farther from the truth.
The human body does not like to lose blood and your arteries contain sticky colorless irregularly shaped bodies, called platelets that go into action when the skin is broken and the body is exposed to air. They gather at the wound and along with calcium, Vitamin K and a protein called fibrinogen, they form a clot to stop the bleeding. These clots are also known as scabs. Sometimes, internal blood clots are formed in response to some trauma to the body that does not break the skin and you get a bruise, or black-and-blue mark, which is the result of an internal blood clot. When a blood clot forms inside a blood vessel, it can block the flow of blood, cutting off the supply of oxygen. If this happens in your brain, it is called a stroke. If it happens inside a main artery supplying blood to your heart, a heart attack will result.
Aspirin (acetylsalicylic acid) inhibits the ability of the blood platelets to aggregate or stick together. The purpose is to prevent blood clots in the arteries and thus aspirin is truly a blood thinner. Plavix (clopidogel bisulphate) is a prescription drug that does exactly what aspirin does at about 100 times the price. Because aspirin reduces platelet aggregation and can actually cause ulceration of the stomach, it would only be available on prescription if it were discovered today.
Coumadin, (warfarin) or as some people call it, “rat poison,” is the main drug used to thin your blood and prevent heart attacks and strokes. It works by inhibiting the synthesis of vitamin K and clotting factors and in a different way prevents your blood from forming clots. Coumadin is also a very difficult drug for your liver to detoxify and people on this drug must be very careful of taking other medications with it, especially Tylenol (acetaminophen) remedies or alcohol. These drugs and other drugs in their class are the true blood thinners and there are not any herbs that work in this fashion. The following, however, have all been labeled blood thinners in at least one or two health books.
White willow bark contains salicylates, which are less than 1/10th the potency of acetylsalicylic acid (aspirin) and its effect on blood platelet aggregation is so minimal it cannot even be measured.
Niacin causes an increase in blood flow and even flushing sometimes but it does this by dilating the arteries. This expansion of the arteries results in a large temporary increase in blood flow, which does not last as the arteries eventually return to their original size. Gingko biloba works exactly in the same manner and if taken on an empty stomach, breaks down and starts its action very early and dilates the blood vessels going upward toward your face and brain. This increase in upward blood flow to your ears helps treat balance, dizziness and, in some cases, ear conditions like tinnitus. The increase in blood flow to your brain helps short-term memory.
Co-Q10 is a unique enzyme in our bodies that lowers resistance to blood flow. Through a series of chemical reactions, it smoothes out the walls of the arteries and when there is less resistance to the flow of the blood, more is pumped through and more oxygen is delivered. It works primarily in the arteries that supply blood to your heart.
Garlic is a substance that does not increase blood flow but like hawthorn, lowers intracellular pressure and thus it is effective in maintaining a lower blood pressure. It has no activity on your platelets and does not thin your blood.
Vitamin E is an excellent anti-oxidant which increases the efficiency of the hemoglobin in your red cells to pick up extra molecules of oxygen. It thus oxygenates your blood or makes it richer and delivers this extra oxygen to the muscles of the body, primarily your heart muscle and your brain.
Most physicians are just as ignorant and they also assume that if a supplement causes an increase in blood flow, it must do so by reducing platelet aggregation. That is why they usually tell you to stop all your supplements before any type of surgical procedure. Even though they may give you Coumadin, which has huge side effects and could result in unstoppable external bleeding, they ask you to stop your Vitamin E and Co Q10. If you drink excessive amounts of alcohol, tell your physician before Coumadin is prescribed because if a heavy drinker takes Coumadin, they most certainly will suffer a cerebral hemorrhage.
If you are taking a blood thinner, do not be frightened by the health gurus who warn you about the blood thinning properties of herbs. However if you stop them for a few days because your surgeon or hospital says so, you will certainly not be at risk.
As a pharmacist I am highly trained in pharmacology, which is the science of how drugs work in your body and all the mechanisms that allow them to perform their actions. On the other hand, physicians take one half year course in pharmacology during their seven years of medical school. The rest of their pharmacological information is supplied by sales representatives who offer biased information which they rarely check .I believe that I know a lot more about drugs than most physicians and especially a lot more about supplements.
Always be a wise consumer and do not believe everything you read. Get second and third opinions, do research on your own, and then make an informed decision about the supplements that you decide to take.