Dangerous combinations

The health foods industry is large and diverse, and a lot of people take different types of dietary supplements and herbal remedies. Whether they are necessary or have any effect what so ever, is much discussed, but we still take them, just in case. And natural herbal products can’t hurt, can they?

Like mixing wine and beer
In the doctor’s office, we find posters urging us to tell our doctor which health food products we eat. And there is a reason for that: Herbal remedies and medication affect one another in your body. It is almost like mixing wine and beer – the effect is unpredictable and not always positive. The result could in the worst case be fatal.

Like if you wish to increase the effect of Viagra by flushing it down with grapefruit juice – tempting, perhaps, but the adverse effects could include both angina and cardiac infarction. Or if you take some St John’s Wort as a tranquilizer – the Viagra might not live up to your expectations.

St John’s Wort basically kills a lot of medication, and women need to keep in mind that birth control pills are not reliable in this combination.

How on earth are we as consumers supposed to know which combinations produce which effects?

Testing popular herbs
Help is on its way: A group of research scientists at the Faculty of Medicine at NTNU are establishing methods that could reveal which combinations of herbs and medication that are harmful and which are safe. The project is financed by the Research Council of Norway and the Norwegian Cancer Society.

“We are testing what happens when mixing popular herbs with ordinary medication,” says Project Manager and Professor Odd Georg Nilsen.

”We cannot say for sure whether garlic strengthens our immune system. But we will provide an answer to whether garlic and other herbal remedies alter the effect of ordinary medication. Our current information on the combined effects of herbal remedies and medication is highly insufficient. Particularly considering the fact that the Norwegian Medicines Agency has an overview of herbs that classifies several hundred different products as merchandise or medication over the counter or on prescription.”

Digestive soup
Anything you eat, be it food, drink or medication, goes down into your stomach and through the digestive organs. Everything is put into the same soup of gastric acid, digestive enzymes and so on.

If you are sick and need medication, the effect depends upon the dosage being right for you. Often, the dose must be adjusted according to any other medication. Ordinary drugs affect one another, and your doctor will check in the Physician’s Desk Reference (PDR) whether the medication you are taking will work together. Some drugs intensify each other while others weaken each other. Perhaps you need a double dose to get the desired effect? Your doctor knows this.

However, if you take herbal remedies together with your medication, there is very little information in the PDR that will tell you and your doctor whether the combination will affect your medicating.

No queuing in your body
The researchers aim to produce a systematic overview of the effects different herbal remedies could have in combination with different drugs. The methods they are using will reveal whether the herbal remedies need to queue up with different drugs on their way through our bodies.

It is when the drugs and the herbs are fighting for space in the body’s systems that the effect of the drugs is influenced. This competition mainly takes place in the intestines and the liver. The intestines regulate how quickly the drugs are absorbed into the body. The liver consists of enzymes that regulate how quickly medication is broken down and filtrated from your body.

”We all know what it is like when there is a queue in front of a door,” Nilsen says. “People are piling up, and the strongest or most impertinent ones get in first. It is the same with herbal remedies and medication standing in front of the same gate and wanting to go through.”

If the herbal remedy is the strongest, the medication will move more slowly to the place where it is needed. The result is reduced or delayed effect. If it is the filtration that is restrained, the medication could accumulate and cause a stronger effect, perhaps with adverse effects.

The testing is performed in different test systems in the laboratory. Cells from intestines and the liver are fed with a combination of herbal remedies and medication, and then it is possible to measure who wins the battle of the cells’ favour.

Testing directly from the case
Medical mathematics is not simple. If the researchers extract two substances from a herb and test how these affect the effect of a drug, the effects could be totally different when testing each substance separately compared to testing them both as a mixed product. The substances in a herbal remedy could change their effect on drugs if they are removed from their natural surroundings.
”We are taking the consequences of this fact,” says Nilsen.
”We are investigating the effect of extracts from the full preparation as it is sold in health food stores and at the chemist’s. You could say that we are testing directly from the case.”
”It is important to remember that drugs and herbal remedies that are said to have identical effects not necessarily reinforce one another, but could actually have the opposite effect,” says Professor Odd Georg Nilsen.

”The rule about caution still applies. And remember to tell your doctor about what you eat!”

Makes the doctor’s work difficult
In general, we can say that medication with a so-called narrow therapeutic width are poorly suited in combination with herbal remedies. The effect of these drugs depends upon a constant amount being in the blood at all times. Several drugs taken in connection with organ transplants, HIV, mental illnesses, epilepsy and cancer are of this type.

If we combine this type of medication with herbal remedies that affect the amount of drug in our blood, the effect of the drug could increase or decrease. An increase could produce undesirable adverse effects while a decrease could result in the therapeutic effect failing to appear.

”It is not always possible to know what could be dangerous,” Nilsen stresses. ”If you for instance just had a kidney or liver transplant, you need to stay away from St John’s Wort.”

Organ rejection is one of the problems that could arise. St John’s Wort is an example of a herbal remedy that weakens the drug that is supposed to make new organs blend into their new surroundings. And it is not enough to avoid taking the herbal remedy the day before the operation. The effect of the product could last for weeks.

Examples of horror are numerous. Many patients being hospitalized, particularly in the US, have taken herbal remedies before undergoing planned surgery. That could make the anaesthetist’s job difficult, and make the result of the operation unpredictable. The herbal remedy Valerian, which many people take to calm their nerves, could increase the effect of the anaesthesia, while Gingko biloba could weaken it. Ginkgo biloba has also proven to produce increased bleeding tendencies during and after surgery.

Tea and mushrooms with adverse effects
Nearly half of all cancer patients in Norway resort to herbal remedies to strengthen their health. As many as 70 percent admit to taking herbal remedies to boost their immune system, and the majority hope for improved quality of life. Nobody has told them that the herbs could weaken the effect of the cancer medication.

In cooperation with the hospitals in Ålesund and Volda, researchers at NTNU have mapped cancer patients’ use of herbal remedies. Most of them place their confidence in garlic and green tea. Noni juice is also popular. Even though none of the patients say that they have noticed any adverse affects of the herbal products, researchers have discovered that green tea could increase the effect of certain cancer medication and thus increase the risk of adverse effects.

Several cancer patients take a product called Agaricus – a Japanese mushroom extract with a price per litre of some NOK 5000. In other words, you have to dig deep into your pocket to enjoy this drink. With a price like that it would be nice to know whether the product affects your health.

”In our studies, Agaricus seems to increase the effect of other cancer medication,” says Research Fellow Silje Engdal. “It is highly worrying that the patients are ripped off financially at the same time as the risk of adverse affects increases.”

List of herbs in the PDR?
”We already know that the St John’s Wort could reduce the effect of cancer medication so much that it does not produce the desired effect,” Engedal says. “Now we know more about how many cancer patients actually use the herbal remedy, which remedies they choose and whether they tell their doctor about it. This information enables us to find out more systematically which combinations the patients need to avoid.”

”At the same time, the doctors could have a list of the herbal remedies they should instruct their patients to avoid. We also have a long-term goal of including a list of herbal remedies in the PDR.”

The project funding ends in 2008, but Nilsen is hoping for prolongation and that a permanent group could be established within this field.

The East meets the West
Numerous herbal remedies come from the East. The Chinese have used herbs for medical purposes for thousands of years and have a somewhat different view on the use of herbs in combination with drugs. If a certain herb is known to strengthen the effect of a particular drug, the treatment will be performed using a lower dose of medication in combination with the herb in question. The idea is that you will have less adverse affects from the medication since you take less of it, while obtaining full therapeutic effect.

Nilsen and his research team are currently cooperating with several research institutions in China on combination therapy with herbs and drugs.

”Chinese and herbal remedies are coming into Western medicine. That makes it important to investigate the effect these might have on Western medication,” the Professor concludes.

By Hege J. Tunstad