Evaluation of Evidence

Once a drug is marketed it leaves the secure and protected scientific environment of clinical trials and is free for consumption by the general public. At this point most medicines will only have been tested for short-term safety and efficacy on a limited number of carefully selected individuals. A person with drug toxicity has accumulated too much of medication in the bloodstream. Hence the need of Pharmacovigilance arises which includes securing the early detection of new adverse reactions or patients subgroups of exceptional sensitivity; and introducing certain measures in order to manage such risks. The field of Patients‟ drug safety has been receiving a great deal of attention since adverse drug reactions are recognized as hazards of drug therapy. In addition adverse drug reactions have a major impact on public health by imposing a considerable economic burden on patients societyand the already stretched health care system.