Phase 4 clinical trial also called as

Phase IV: Postmarketing surveillance/ studies After the drug has been marketed for general use, practicing physicians are identified through whom data are collected on a structured proforma about the efficacy, acceptability and adverse effects of the drug. Uncommon/idiosyncratic adverse effects, or those that occur only after long-term use and unsuspected drug interactions are detected at this stage. Ref:- kd tripathi; pg num:-80