Q: What is Phase 4 trial of any given drug?
Answer: Relatively less publicised and less talked is the evaluation of a drug profile after it is approved and already in the market for patients. It looks over the time the efficiency and the side effects of a new drug/treatment. Usually, it is carried out over a longer period of time and look over thousands of patients.
Suvarna V. Phase IV of Drug Development. Perspectives in Clinical Research. 2010;1(2):57-60.