Post-Marketing Drug Surveillance

Post-marketing surveillance is the continuous monitoring of a medicine after it is approved and used by the wider population. Its safety arm, pharmacovigilance, identifies adverse effects and other medicine-related problems, while quality surveillance checks whether marketed batches continue to meet prescribed standards.

Detecting safety signals

Pre-approval trials may not reveal rare, delayed or population-specific harms because their duration and participant numbers are limited. Surveillance therefore examines medicine use under real-world conditions.

• Patients, healthcare professionals and manufacturers submit suspected adverse drug reaction reports, describing the medicine, event, timing and relevant clinical details.
• Authorities aggregate reports to identify a safety signal, such as an unusual event, a reporting cluster or a disproportionate reporting pattern.
• Signals may also emerge from observational studies, registries, published literature and periodic safety information submitted by manufacturers.
• A signal is not proof of causation. It is assessed for temporal association, alternative explanations, consistency across reports and available clinical evidence.

Detecting quality defects

Quality surveillance focuses on whether the product actually sold conforms to its approved specifications throughout its shelf life.

• Drug inspectors collect market samples, which authorised laboratories test for identity, strength, purity, dissolution and sterility, where applicable.
• Complaints, inspection findings, stability data and manufacturing records can reveal contamination, incorrect labelling, packaging defects or not-of-standard-quality batches.
• Batch numbers and distribution records help regulators trace affected products and determine whether a defect is isolated or widespread.

Assessment and regulatory response in India

The Pharmacovigilance Programme of India, coordinated by the Indian Pharmacopoeia Commission, collects and analyses adverse reaction reports and communicates safety findings to the Central Drugs Standard Control Organisation.

• A validated problem may lead to additional studies, safety warnings, label changes or restrictions on use.
• A quality failure may result in batch recall, inspection, corrective action, suspension or other regulatory proceedings under the Drugs and Cosmetics Act, 1940 and associated rules.
• Continued monitoring then evaluates whether these measures have reduced the identified risk.