The methodology of safety data in clinical trials

Only Type A adverse drug reactions are likely to be detected during the pre-marketing clinical trial programme. The collection of adverse events may be by spontaneous reporting, a standard general question, a checklist, a self-answering questionnaire or a quality of life questionnaire. From these one needs to differentiate the adverse reactions due to the experimental drug from the ordinary every-day minor events occurring in healthy individuals, the adverse events relation to the target disease, the adverse events related to concurrent illnesses, the adverse reactions due to concomitant therapy and adverse events engendered by the comparator drugs or placebo. It is important to realise that the patients on the experimental drug may be infected with adverse reactions by the patients on the comparator drug. A post-treatment visit enables the doctor to check the laboratory investigations from the last visit whilst on treatment, any withdrawal symptoms from the drug, delayed adverse drug reactions, the response to dechallenge of any adverse reaction and arrange for follow-up of any problems or rechallenge. (Ref. 10).