Introduction

Genetic diversity contributes to both disease susceptibility and variability in response to drug therapy. Pharmacogenomics is a discipline focused on examining the genetic basis for individual variations in response to therapeutics (1-4). Although the task of developing individualized medicines tailored to patient's genotypes poses a major scientific challenge, pharmacogenomics is already starting to influence how physicians/scientists design clinical trials and its impact on the practice of medicine is forthcoming (5,6). Recent evidence suggests that most prescribed medications are effective in no more than 60% of the individuals in whom they are used, and a significant number of patients also develop major adverse effects. Better understanding of the genetic factors that regulate patient's responsiveness to drugs is therefore needed to elucidate the molecular mechanisms involved and allow for development of new therapeutic strategies that match each patient and the most suitable drug (7-9).

While drug treatment constitutes the mainstay of medicine, for most drugs, there is considerable variability in patient's therapeutic response (2,3). In other cases, unforeseen serious side effects may occur (10,11). For the patient this represents a dangerous and potentially life-threatening situation, and, at the societal level, adverse drug reactions are the most common cause of hospital admissions in the elderly and represent a leading cause of disease and death (12). In some cases, genetic variations have been shown to influence both efficacy and safety profiles, as in the case of dicumarol, warfarin, or isoniazid, wherein patient variation in response to these drugs can largely be attributed to polymorphisms in the CYP450 gene family that confer rapid versus slow acetylation of these drugs (10). Since genetic variations can lead to differences in the regulatory functions of genes, variability in their mRNA and/or protein expressions may follow. Pharmacogenomics is charged with measuring these differences in mRNA and protein messages in response to drugs, and although relatively few examples of success exist, this approach holds the promise that we may be able to profile these variations in individuals' genetic makeup and accurately predict response to drugs addressing both efficacy and safety issues (3,4,6,9,10).

In recent years, microarray technology has revolutionized almost all fields of biomedical research by enabling high-throughput gene expression profiling in a single experiment, thereby allowing thousands of genes in different species to be examined in the context of organ differentiation and development in search for disease susceptibility genes and new targets in drug discovery. With the use of expression microarray, the future holds the promise that we may soon gain more global understanding of gene expression changes with respect to disease susceptibility and progression and that biomarkers will become increasingly used as diagnostic and prognostic indicators of treatment response and also provide new insights into the process of new target discovery.

A brief overview of some of the key examples of pharmacogenetic effects follows. This is designed to give the reader an initial idea of the potential for pharmacogenetic effects to contribute to disease management. Fuller accounts of the range of pharmacogenetic effects relevant to each major disease group can be found in the chapters that follow.

Cure Your Yeast Infection For Good

Cure Your Yeast Infection For Good

The term vaginitis is one that is applied to any inflammation or infection of the vagina, and there are many different conditions that are categorized together under this ‘broad’ heading, including bacterial vaginosis, trichomoniasis and non-infectious vaginitis.

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