No abstract available.

No abstract available.

The third equation on page 44 should be corrected.

The equations on page 162 should be corrected.

In the published version of this article, the contents of Table 1 (‘Demographic characteristics of subjects’) are incorrect.

The number of clinical trials sponsored by global pharmaceutical companies performed in countries other than the U.S. and Western Europe has been steadily increasing over the past decade. Among those emerging countries, Korea deserves attention for its rapid growth in the number of trials and sites. As of 2009, Korea was ranked the tenth country in the number of clinical trials registered at http://clinicaltrials.gov. This is remarkable growth given that it was not included in the top 30 countries in 2005. High population density, qualified medical professionals, regulatory changes including Investigational New Drug-New Drug Application (IND/NDA) separation, acceptance of International Conferences on Harmonization-Good Clinical Practices (ICH-GCP) by Korea Food&Drug Administration (KFDA), and governmental policies to boost clinical trials were the most influential factors that caused such an outstanding achievement. The Korean National Enterprise for Clinical Trials (KoNECT), an organization founded to lead initiatives to improve the milieu for clinical trials, has been playing a pivotal role in the steering of 15 regional clinical centers designated by the government. Based upon improvements in infrastructure so far, diversity in therapeutic areas and the proportion of early phase trials are expected to grow. Korea has grown to be one of the major countries in the clinical trial market, which was made possible by the cooperation of industry, academia and government. Further investment and efforts to solve current challenges will allow such growth to continue into the next decade.
Achievement ; Congresses as Topic ; Europe ; Investments ; Korea ; Population Density

More than 60 antiviral agents for various infectious diseases such as herpes, hepatitis, influenza, and AIDS are currently prescribed worldwide. Among the viral infections, hepatitis B and influenza are those frequently seen in primary care situations in Korea. This review discusses the anti-hepatitis B (HBV) drugs entecavir and adefovir, and the anti-influenza drugs oseltamivir and zanamivir. In addition, the pharmacology and therapeutic guidance suggested by the Korean Association for the Study of the Liver were reviewed for entecavir and adepovir, the most frequently prescribed anti-HBV drugs. For influenza, oseltamivir is commonly used despite debates on neuropsychiatric safety issues and zanamivir may be used when an inhalation form is necessary. Although currently used drugs show considerable clinical efficacy, efforts to optimize their use and further research to find new molecules that may overcome their limitations are necessary.
Adenine ; Antiviral Agents ; Communicable Diseases ; Guanine ; Hepatitis ; Hepatitis B ; Influenza, Human ; Inhalation ; Korea ; Liver ; Organophosphonates ; Oseltamivir ; Primary Health Care ; Zanamivir

This tutorial deals with basic concepts of volume of distribution, the second most important parameter in pharmacokinetics but often challenging for students in clinical pharmacology. Its relationships with dose, concentration and amount in the body are discussed using a physical model and examples of commonly used drugs, as well as its physiological aspects pertaining to the physical volume of differing organs. Finally, application of volume of distribution to the calculation of loading dose and half-life is used to show how it is essential in pharmacotherapy and clinical pharmacology.
Drug Therapy ; Half-Life ; Humans ; Pharmacokinetics ; Pharmacology, Clinical

Drug-drug interaction (DDI) is defined as a change in effect or safety of a drug by another co-administered drug. The fact that more than half of the market withdrawal cases for the past ten years was caused by potentially fatal DDI's demonstrates its clinical importance. The mechanism of DDI can be categorized into pharmacokinetic and pharmacodynamic interactions. Most of the clinically important drug interactions are caused by inhibition or induction of oxidative metabolism by cytochrome P450 (CYP) isozymes. Recent researches are also focusing on drug transporter interactions as another significant factor underlying DDI's. It is hard to prevent unexpected or rare DDI's. However, most of the cases of DDI occur from an erroneous prescription of drugs that are already known to result in deleterious interactions. To avoid such well-established DDI's, physicians are first recommended to utilize hands-on summary tables for CYP substrates before prescribing. It should also be remembered that old age, polypharmacy and damaged hepatic or renal function are risk factors of DDI as well as adverse drug reactions. Moreover, patients treated with drugs with a narrow therapeutic index (immunosuppressants, antiarrhythmics, anticoagulants, digoxin, theophylline etc) deserve a special consideration when their prescriptions are changed. In Korea, the clinical significance of DDI has been underemphasized. The fundamental prescription to this old prescription habit is to teach medical students and physicians clinical pharmacology and therapeutics, which have long been neglected in Korea.
Anticoagulants ; Cytochrome P-450 Enzyme System ; Digoxin ; Drug Interactions ; Drug-Related Side Effects and Adverse Reactions ; Humans ; Isoenzymes ; Korea ; Metabolism ; Pharmacology, Clinical ; Polypharmacy ; Prescriptions ; Product Recalls and Withdrawals ; Risk Factors ; Students, Medical ; Theophylline

This tutorial deals with basic concepts of clearance, the most important parameter in pharmacokinetics but often challenging for students in clinical pharmacology. Its relationships with dose, concentration and elimination rate are discussed using a physical model and examples of commonly used drugs, as well as its physiological aspects pertaining to the blood flow to differing organs. Finally, application of clearance to the calculation of maintenance dose rate and half-life is used to show how it is essential in pharmacotherapy and clinical pharmacology.
Drug Therapy ; Half-Life ; Humans ; Pharmacokinetics ; Pharmacology, Clinical