Although complementary medicines are often considered less powerful than prescription medicines, they can still cause side effects in some people and may interact with other medicines and foods. Therefore, they should be given the same consideration as other medicines.

Selecting any medicine involves answering several key questions, including:

• Is a medicine needed?
  
• How effective is the medicine for my condition or situation?
  
• What are its possible side effects?
  
• Does it interact with any other medicines or foods?
  
• What is the right dose for my condition or situation?
  

For most prescription medicines and some medicines bought from pharmacies and supermarkets, it is possible to get answers to these questions. In Australia, such medicines have to undergo scientific testing that addresses these questions, and the information is publicly available.

However, the situation is different for most complementary medicines. In general, they have been subjected to less testing, so the answers are less certain. Also, the information that is available is often harder to find.

Finding the answers

So, how do you get the information you need?

GPs and pharmacists are more open to discussing complementary medicines than they were in the past. Ask your GP, pharmacist or complementary health care provider about the medicine and whether they think it might be beneficial for you.

The medicine label will also provide some information, but it may not be very detailed.

There are thousands of websites that provide information about complementary medicines. However, most are designed to sell a product, so they may present only information that makes their product more appealing. Only a limited number provide reliable and balanced information that presents both sides of the story. To get the best information, look for websites that appear to present information in an unbiased way. Some good websites include:

• Medline Plus herbs and supplements
• myDr
• US National Institutes of Health National Center for Complementary and Alternative Medicine
• HealthInsite.
  

Each of these sites has information about many different complementary medicines.

Assessing the information

Having found your information, you need to go through it to see if it answers the five key questions.

Is a medicine needed?

Medicines are not always the most appropriate treatment or way of preventing a condition. Sometimes other approaches may be more appropriate. For some conditions relaxation therapy, physiotherapy, counselling or changing your diet may be equally or more effective.

How effective is the medicine for my condition or situation?

No medicine is a universal cure, so you need to find out if the medicine works for your condition.

Take fish oil for example. Fish oil is one of the more studied complementary medicines. Hundreds of studies have been conducted to determine its effectiveness in treating or preventing a wide variety of conditions. However, for almost all the conditions studied, the results have not provided conclusive evidence about its effectiveness.

The only exception is the treatment of high triglyceride levels. Research has shown that fish oil may lower the levels of triglyercides (one type of fat in the blood) in people who have high levels.

To help you sift through all the information available, some good quality websites tell you how likely it is that a medicine is an effective treatment for a particular condition. They do this by rating the ‘strength of the evidence’ for the medicine. For example, they might rate a medicine as being ‘effective’ for one condition, ‘possibly effective’ for another, and ‘ineffective’ for another depending on how conclusive the research is. Using these ratings can help you to decide whether a particular medicine might be worth considering for your condition.

For example, according to the US National Institutes of Health National Center for Complementary and Alternative Medicine website, fish oil is ‘likely effective’ for preventing heart disease and heart attacks, but only ‘possibly effective’ for treating depression.

What are its possible side effects?

Although complementary medicines generally cause fewer side effects than prescription medicines, no medicine — even ‘natural and herbal medicines’ — is completely free of side effects.

For example, valerian, a herb that is sometimes used to improve sleep, can cause headaches and vivid dreams. Echinacea, which is sometimes used to ward off infections and reduce the duration of colds, may worsen asthma.

Does it interact with any other medicines or foods?

Like all medicines, complementary medicines sometimes interact with other medicines and foods.

St John’s wort is found in many complementary medicine products used to alleviate depression. It can interact with several commonly used prescription medicines, including the oral contraceptive pill, the heart medicine digoxin, the blood-thinning medicine warfarin, and some other antidepressant medicines. Some of these interactions result in the prescription medicine not working as well, while others increase the likelihood of experiencing side effects from the prescription medicine.

What is the right dose for my condition or situation?

You need to take enough of a medicine for it to be effective. However, you don’t want to take any more than you need, because doing so increases your likelihood of developing side effects, and it’s money down the drain.

For complementary medicines, finding out the right dose can be particularly difficult. Even good sources of information can be quite vague or contradictory about how much and for how long you should take the medicine.

As with other medicines, the right dose may depend on the condition for which it is being used. Follow the recommendations on the medicine label, and don’t be tempted to take more than the recommended dose. If you’re unsure about what dose to take and for how long to take it, ask your GP, pharmacist or complementary health practitioner for advice.

Tell your doctor and pharmacist

Your doctor and pharmacist need to know about all your medicines, so they can consider any possible interactions when recommending medicines for you. Make sure you tell them about any complementary medicines you are taking, and include them on your NPS Medicines List.