New Delhi: Unexpected side effects of medicines often emerge only after extensive use of a medicine. To strengthen monitoring of such cases, India’s drug regulator has directed pharmaceutical companies to maintain robust systems for tracking and reporting adverse reactions associated with drugs sold in the market.In a circular issued on June 3, the Central Drugs Standard Control Organization (CDSCO) reminded drug manufacturers and other stakeholders that they need to establish and maintain effective pharmacovigilance systems to collect and report adverse drug reactions associated with the drugs they manufacture or market.The regulator said the requirement comes from the provisions of Schedule M of the Drugs and Cosmetics Rules, which mandate that license holders maintain systems for collecting, processing and forwarding reports of adverse drug reactions to licensing authorities.Experts said Schedule M prescribes good manufacturing practices (GMP) that pharmaceutical companies are required to follow. The latest emphasis on pharmacovigilance reinforces the need for robust post-marketing surveillance to monitor the safety of drugs once they reach patients, often referred to as Phase IV surveillance.“Pharmacovigilance helps detect new or previously unknown adverse reactions at an early stage, allowing regulators and manufacturers to take timely action,” the experts said.While drugs undergo clinical trials before approval, some side effects may only become apparent when they are used by large numbers of patients in a real-world setting. Monitoring such reactions helps identify emerging safety concerns and strengthen patient safety.CDSCO said all stakeholders should ensure compliance with the provisions of the Drugs and Cosmetics Act and Rules as well as the New Drugs and Clinical Trials Rules, 2019.The regulator also said that CDSCO, state licensing authorities and Union Territory administration officials may verify compliance during routine inspections and other regulatory activities.The move comes amid a growing global emphasis on post-marketing surveillance as regulators increasingly rely on real-world safety data to identify rare or delayed adverse reactions associated with drugs.