Pharmacovigilance (PV), or the science of drug safety, is a continuous, systematic discipline dedicated to the detection, assessment, understanding, and prevention of adverse effects or any other medicine-related problem.

It is an essential component of the entire drug lifecycle, beginning during the earliest stages of clinical development and continuing throughout the many years a medication is available for patient use. The core goal is to improve patient care and safety in relation to the use of medicines and, consequently, improve public health.

Limitations of Clinical Trials and the Need for Real-World Surveillance

The necessity for robust PV systems arises from the intrinsic limitations of pre-approval clinical trials. These studies, while rigorous, are conducted on a relatively small number of highly selected patients under controlled conditions and for a finite duration. This structure means they cannot comprehensively capture several critical safety issues:

• Rarity of Events: Very rare adverse drug reactions may not occur in a trial population until the medication is used by millions of people in the general population.

• Long-Term Effects: Adverse effects that only emerge after prolonged exposure to a drug, potentially years after treatment begins, cannot be detected during short-term trials.

• Real-World Variability: Trials exclude patients with multiple co-morbidities, those taking many other medications, and specific vulnerable groups (such as children, the elderly, or pregnant women). When the drug is released to the general public, it is used by these diverse populations, where unforeseen drug-drug interactions or safety signals may arise