postmarketing adverse drug event

Postmarketing adverse drug events are unanticipated or unwanted effects of drugs that may not be identified during clinical trials before a drug is marketed. These events can be dose-dependent, occurring when a drug is taken in high doses, or dose-independent, often resulting from allergic reactions.12

Identifying these events can be challenging, as symptoms like fever or liver inflammation can have other causes. Procedures exist to determine if an event is related to drug use, such as observing if symptoms disappear when the drug is stopped. However, for serious adverse events, reintroducing the drug to confirm a link is not advisable. This difficulty can lead to drug-induced adverse events going unrecognized for extended periods, sometimes resulting in criticism for delayed public warnings.1