DRUG EVALUATION IN CLINICAL PRACTICE
FDA has established the Centers for Drug Evaluation and Research (CDER) to evaluate new drugs before they can be sold. The aim of drug evaluation is to prevent quackery and to provide the necessary information to the doctors and patients so that they can use the drugs wisely. Drug evaluation process ensures that both branded and generic drugs work correctly and their benefits outweigh their risks. The pharmaceutical companies test their drugs to prove their safety and effectiveness for the intended use. The results of these tests are then shared with the CRERs where clinicians, statisticians, chemists, pharmacologists and other pharmacy professionals review the provided data. If the independent and unbiased review establishes the health benefits of the drug, it is approved for sale. Once the New Drug Application (NDA) is submitted to the FDA by the company for drug evaluation, it may take two months to seven years for final marketing approval. Overall, the drug evaluation process scrutinizes everything about the drug from the clinical trial design, severity of the side effects and the conditions under which the drug is manufactured (U.S. FDA).
DRUG MONITORING IN CLINICAL PRACTICE
The aim of drug monitoring is to achieve maximum therapeutic benefit from a drug while keeping the side effects to a minimum. It is useful in assessing the efficacy and toxicity of the drugs. The serum levels of the drug are measured to ensure its concentration within the therapeutic range. It is useful in case of a) drugs with narrow therapeutic index, b) patients with impaired clearance of the drug, c) drugs whose toxicity is difficult to distinguish from a patient’s disease and d) drugs in which establishment of clinical efficacy is difficult. Overall, drug monitoring may be useful to guide dosage adjustment of drugs in some patients.
DRUG SAFETY IN CLINICAL PRACTICE
When a pharmaceutical company develops a new drug product, it files Investigational New Drug Application (IND) with the FDA. Once the IND is reviewd and approved by the FDA, a new drug product passes through three distinct phases of clinical trials before it can be marketed. These phases are referred to as phase I, II and II clinical trials. Phase I or clinical pharmacology phase identifies the basic safety profile of the drug in humans. It may involve 20 to 80 healthy volunteers. Phase II involves as many as 200 patients with actual disease to be treated. This phase evaluates the efficacy of the drug product. Phase III involves up to 1000 patients and aims at gathering the effectiveness data, adverse drug reaction data and safety information about the drug. Overall, the safety of a new drug is evaluated in phase I and phase III clinical trials (U.S. FDA).
PHARMACOEPIDEMIOLOGY
Pharmacoepidemiology is a discipline of pharmaceutical sciences that provides valuable information about the health and cost outcomes of drugs, medical devices and biologicals. It studies the use and (beneficial as well as harmful) effect of drugs in large numbers of people. It uses automated and linked databases allowing rapid and efficient studies of drug effects. Pharmacoepidemiology uses two types of study designs viz. experimental and observational designs. Experimental designs expose the individuals under investigations to the drug, device or biological and then follow ups the individuals for the detection of the effects of exposure. Observational designs include case controlled, cohort and cross-sectional studies and are more commonly used than experimental designs. Pharmacoepidemiological studies provide important information to support the optimization of therapeutic responses to the drugs (DiPiro, Talbert, Yee, Matzke, Wells and Posey 115).
PHARMACOVIGILANCE
Pharamcovigilance is the branch of pharmaceutical sciences that detects, assesses, understands and prevents the adverse drug effects or drug-related problems. It refers to the continued monitoring for unwanted effects and safety-related aspects of the marketed drugs. The aims of phamacovigilance are to enhance patient care and patient safety wrt the use of medicines and to support the public health programmes by providing reliable information about risk-benefit profiles of the drugs. The concerns of pharmacovigilance have been widened to include herbals, traditional medicines, blood products, biologicals, medical devices and vaccines. Pharmacovigilance centers across the nations coordinate the post marketing surveillance and collect & analyze case reports of adverse drug reactions, make regulatory decisions and alert prescribers, manufacturers and the public to new risks of adverse reactions (World Health Organization 7).
PHARMACOECONOMICS
Pharmacoeconomics is the discipline of clinical pharmacology that identifies, measures and compares the cost of drug therapy to healthcare systems and society. It uses the economic valuation methods such as cost minimization, cost utility, cost benefit and cost effectiveness analysis. Pharmacoeconomic methods are applied for individual patient treatment, effective formulary management, medication policy determination and resource allocation. Pharmacoeconomic information assists the clinical decision makers in choosing the cost-effective treatment options (DiPiro, Talbert, Yee, Matzke, Wells and Posey 1).
Works Cited
DiPiro, J. T., Talbert, R. L., Yee, G. C., Matzke, G. R., Wells, B. G. and Posey, L. M. Pharmacotherapy: A pathophysiologic approach. 6th ed. New York: McGrw Hill, 2005. Print.
U.S. Food and Drug Administration. Development and approval process (Drugs). U.S. department of health and Human services. 23 Oct 2013. Web. 16 Jun 2014.
U.S. Food and Drug Administration. The FDA's Drug Review Process: Ensuring Drugs Are Safe and Effective. U.S. department of health and Human services. 28 May 2014. Web. 16 Jun 2014.
World Health Organization. The importance of pharmacovigilance: Safety monitoring of medicinal products. WHO 2002. Web. 16 Jun 2014.
