Int. J. Pharm. Sci. Rev. Res., 28(2), September – October 2014; Article No. 18, Pages: 95-100 ISSN 0976 – 044X International Journal of Pharmaceutical Sciences Review and Research Available online at www.globalresearchonline.net © Copyright protected. Unauthorised republication, reproduction, distribution, dissemination and copying of this document in whole or in part is strictly prohibited. © Copyright pro 95 Satish Chandel* , Nidhi Jain, Abhay Joshi, Rakesh Sonawane, Arvind Sharma, Satish Chandel Department of Pharmacology, Gandhi Medical College, Bhopal, India. * Corresponding author’s E-mail: dr.satishchandel@gmail.com Accepted on: 24-07-2014; Finalized on: 30-09-2014. ABSTRACT Signal detection is important and core activity of pharmacovigilance. The primary aims of pharmacovigilance are to collect, monitor, assess and evaluate information regarding adverse effects, especially those which are serious or unexpected; and also involve providing information about potential and investible hazards. The signal detection and its dissemination seem to be important utility of pharmacovigilance database. It has power to prevent the epidemics of serious adverse drug reaction before gross damage to community. The historical medical calamities could have been prevented if technique like signal detection and pharmacovigilance would have been practiced since that time. Keywords: Adverse drug reaction, Pharmacovigilance, Signal, Bayesian Confidence Propagation Neural Network, Information component. INTRODUCTION rugs are among the miracles of this era. They have saved billions of life and will continue to do same in future. They have helped to bring improved health and longer life to the human. The practice of medicine should be assessable, available, affordable, and most importantly ‘safe’. But we must understand that they are not without risk. Drugs do not always benefit the recipients instead they can harm some times. The damage done by the drugs can range from mild, moderate to severe or life threatening. This harm and damage done by drugs when it is given in dose normally used in men is called adverse drug reaction (ADR). Practically each and every drug can cause adverse drug reaction. World health organization (WHO) has defined adverse drug reaction as “A response to a drug which is noxious and unintended, and which occurs at doses normally used for the prophylaxis, diagnosis or therapy of disease, or for the modification of physiological function”. An adverse event is defined as harmful and inadvertent medical occurrence which may present during treatment, but does not have proven causal relation with drugs. 1 Adverse drug reactions are serious matter concern as it considerably affects morbidity and mortality. Adverse Drug Reactions are the 4 th to 6 th leading cause of mortality in the USA. More than 10% of hospital admissions are concerned with drug related events. More than 20% budget is spent on drug related events. 2 Hence it is very important to identify, monitor and assess and prevent ADRs. The discipline concerned with identification, monitoring and then prevention of ADR is called as pharmacovigilance. WHO defined pharmacovigilance as “The science and activities relating to the detection, evaluation, understanding and prevention of adverse drug reactions or any other drug- related problems”. 3 The aims of pharmacovigilance are early detection of unknown safety problems, identification of risk factors, quantifying risks and ultimately preventing patients from being affected unnecessarily. 4 One of the most important activities of pharmacovigilance is signal detection. The importance of signal detection was recognized after thalidomide disaster in early 1950s, then various efforts were started to prevent such tragedy. The primary function of pharmacovigilance is to recognize early warning with regard to previous adverse effects of drugs. The signal in pharmacovigilance is information of particular ADR with causal relation to a drug which is not reported previously. The WHO has defined a signal as: “Reported information on a possible causal relationship between an adverse event and a drug, the relationship being unknown or incompletely documented previously”. 5 The interpretation that a signal should be seen as a first hint that there is a need to look more closely at a drug and its associated reported ADR was given by Finney in 1974; according to him “A signal is a basis of communication between WHO and national centres; only rarely will it carry the force of a proven danger” and, “Signals are intended to arouse suspicions and to stimulate deeper investigation”. 6 Amery in 1999 also stated that: “A signal may be defined as new information pointing to a previously unknown causal relationship between an adverse event, or its incidence, and a drug: the information must be such that if confirmed, it may lead to action regarding the medicine. 7 Signal is not a confirmatory finding, it require further evaluation and may get approved or neglected. Thus signal generation aims at timely identification of previously unsuspected adverse effects, but any signals require further evaluation Signal Detection - An Imperative Activity of Pharmacovigilance D Research Article