Pharmacovigilance - Finding The Risks of Drugs

Finding The Risks of Drugs

Pharmaceutical companies are required by law in all countries to perform clinical trials, testing new drugs on people before they are made generally available. The manufacturers or their agents usually select a representative sample of patients for whom the drug is designed – at most a few thousand – along with a comparable control group. The control group may receive a placebo and/or another drug that is already marketed for the disease.

The purpose of clinical trials is to discover:

• if a drug works and how well
• if it has any harmful effects, and
• its benefit-harm-risk profile - does it do more good than harm, and how much more? If it has a potential for harm, how probable and how serious is the harm?

Clinical trials do, in general, tell us a good deal about how well a drug works and what potential harm it may cause. They provide information that should be reliable for larger populations with the same characteristics as the trial group - age, gender, state of health, ethnic origin, and so on.

The variables in a clinical trial are specified and controlled and the results relate only to the population of which the trial group is a representative sample. A clinical trial can never tell you the whole story of the effects of a drug in all situations. In fact, nothing could tell you the whole story, but a clinical trial must tell you enough; "enough" being determined by legislation and by contemporary judgements about the acceptable balance of benefit and harm.