What if there was a drug that could completely relieve your pain but carried a 1 in a hundred thousand chance of killing you? Would you try it? What if the chances of death were 1 in a million or 1 in 10,000?

Regardless of what you decide, your decision would likely be based on weighing risk (the chance of dying) against benefit (complete relief of pain). The ability to do this depends on having reliable information on what a drug may do, either beneficial or harmful. (See SIDE EFFECTS)

However, despite its vastness, our knowledge of how drugs interact with the mind and body is still incomplete. Even though we have a solid grasp of some basic principles, there is a layer of uncertainty in the use of many drugs, even as new findings become regularly available. Individual responses to drugs can vary in terms of effectiveness or bad reactions. This is sometimes unpredictable. Knowing what a drug can do is not the same as knowing what it will do in an individual patient.

Drug use is therefore a matter of trial and error, even with well-known drugs. Because of this it is vital that we understand how to weigh risk against benefit. The chance that a drug can cause problems is its risk. The chance that a drug will relieve a problem (e.g. pain) is its benefit. This information is most reliably available from properly conducted research (see TESTING). In order to compare risk and benefit we should also know how severe the adverse effects could be as well as the strength of the positive effects.

One of the biggest problems I see in my medical practice is a misunderstanding of risk and benefit. Some people refuse to take a certain medication without taking into account that the chance of a serious effect occurring may be less than the risk of having a serious car accident. Others may want a certain drug without considering that the chance of it helping is small or untested.

When deciding to take a certain drug or not, keep in mind that you are comparing probabilities when you weigh risk against benefit. Ask health care professionals and direct your searches for details about risk and benefit. Avoid relying on your instinct or intuition without examining yourself first for prejudice or desire. These can easily influence your decision, sometimes wrongly. In the end the decision will be yours.

There is always an element of chance when taking a drug. It makes sense to get all the facts you can before deciding. You may argue that drug taking is a gamble – if so, you need to know the odds to find out if it’s worth it.