Pharmacovigilance has been defined by the WHO (2002) as the ‘science and activities relating to the detection, assessment, understanding and prevention of adverse effect or any other drug related problems.’ The information generated by pham1acovigilance is useful in educating doctors about ADRs and in the official regulation of drug use. Its main purpose is to reduce the risk of drug-related harm to the patient. It has an important role in the rational use of medicines, as it provides the basis for assessing safety o r medicines.
The activities involved in pharmacovigilance are:
a. Post marketing surveillance and other methods of ADR monitoring such as voluntary reporting by doctors (e.g. yellow card system of UK), prescription event monitoring, computerized medical record linkage and other cohort/case control studies as well as anecdotal case reports by doctors. Voluntary reporting depends on the initiative and willingness of the health professionals. It is minimal in India, while even in the developed country only ~ I 0% ADRs are reported voluntarily. Immediately occurring reactions and those that are dramatic are mostly reported. Though even rare reactions can be detected by this method, it does not provide incidence of the reaction.
b. Dissemination of ADR data through ‘drug alerts’. ‘medical letters’ , advisories sent to doctors by pharmaceuticals and regulatory agencies (such as FDA in USA. committee on safety o f medicines in UK).
c. Changes in the labelling of medicines indicating restrictions in use or statuary warning , precautions, or even withdrawal or the drug, by the regulatory decision making authority.
Phamacovigilance centers have been set up in most countries. The Uppsala Monitoring Centre (Sweden) is the international collaborating centre. In India. the Central Drug standard Control Organization (CDSCO) is coordinating the pharmacovigilance programme, under “which peripheral, regional and zonal monitoring centres have been set up along ” with a national Pharmacovigilance advisory committee.
The pharmacovigilance centers collect, communicate and disseminate ADR data by linking with hospitals as well as practitioners and are also expected to provide experts for assessing causality and severity of ADRs by using standard algorithms and rating scales like the ‘ Naranjo algorithm’ (causalihy assessment) and modified Hartwig scale (severity grading).
MCQ on Pharmacovigilance given at the end of Lecture see above lecture