Muhammad Haseeb Tariq, Muhammad Junaid Farrukh, Syed Azhar, Syed Sulaiman, Obaidullah
Drugs are introduced into the market for use by the patients after year’s long drug development processes including extensive clinical trials and stringent approval pathway by drug regulatory authority keeping in view safety, efficacy and quality parameters. Drugs are usually approved after successful completion of phase III clinical trial. Post marketing surveillance or phase-IV clinical trials are focused on long term safety studies and may continue for years. Drugs are withdrawn from the market if serious adverse events appeared even after approvals like withdrawal of rofecoxib [1].