The Role of Post marketing Surveillance in Clinical Trail
Clinical trails containing new drugs are categorized into essential four phases (1). The drug development procedures are usually performed through the all phases over several years (1). The drug will be approved for use in the general population, if it successfully exceeds through the first three phases; I, II, and III. The fourth phase -IV- is called Post marketing Surveillance and/or Post approval studies (2). Postmarketing Surveillance Trial provides the safety surveillance (Pharmacovigilance) (3). phase IV Analytics methods studies may be required by sponsoring companies, when detecting a new drug market or testing the drug interactions with other drugs, and also by regulatory authorities (4). The safety surveillance, which is a very important part of a comprehensive post-marketing program, investigates drugs long term effects in a large number of people (1) (3).
The aims of the post-marketing safety surveillances program are to examine and quantify new drug safety issues, to recognize risk factors of product marketing, and to control medication use patterns (3). If undesirable effects are noticed In this forth phase of trial, the drug might get withdrawn from the market.
Methods of Suveillance Studies:
There are four different types of studies that are mostly conducted to determine drug effects including; controlled clinical trails, spontaneous reports, cohort studies, and case control studies (5).
Controlled clinical trails, which work closely with therapy and study group, minimize bias via specific methods such as: double blinding and randomization. This trial also monitor patients during the study duration. The controlled clinical trails serve as the most powerful method for determining drug's safety and efficacy. However, this method is often costly (23 from).
Spontaneous reports are prepared by pharmaceutical manufactures which are required to inform possible adverse effects of drugs to the Food and Drug Administration (FDA) (50). In cohort studies, there is no double blinding and patients are not randomly involved to studies, so bias is increased. This method follow a assigned group of patients for a specific time. Controls with same medical problem, who are not talking the drug of interest and who may be examined in parallel. If any adverse reactions exist, prospective cohort studies can be performed to define drug's beneficial as well as harmful effects ( 61). Finally, case control studies. In these studies, patients with harmful effects are recognized to be studied and compared with the controls (sample) designed from the same group that provided rise to the cases. Also, Bias is possible in case control studies (77).
Data Collection of Post-marketing Safety Surveillance
Post marketing surveillance uses many available tools, including; Prescription Event Monitoring, Spontaneous Adverse Event Report Databases, Larger Automated...