Pharmacokinetics response variations

Narrow therapeutic index combined with the inter-individual variations in drug pharmacokinetics, response, and toxicity adds uncertainty to the clinical trials and use of novel anticancer agents. Pharmacogenetic and metabolomic profiling of the patients promise to at least partly address these concerns, thus helping in the individualization of medication for patients and improved... 

This volume covers topics including cultural perspectives in psychiatric diagnosis and psychopharmacotherapy, differences in pharmacokinetics and pharmacodynamics of psychotropics, pharmacogenetics of ethnic populations, ethnic variations in psychotropic responses, complementary medicines in mental disorders, attitudes towards psychotropic medications, prescribing practices in Asia-Pacific countries, pharmaco-economic implications, integrating theory and practice, and... 

Ethnic differences have been shown to influence response to psychotropic medications. Much of the focus on the explanation for such differences has been on drug-metabolizing (CYP) enzymes of the liver and their sway over pharmacokinetic factors. It is now well recognized that differences in the distribution of polymorphic variants of CYP enzymes exist between different ethnic groups. However, within ethnic groups there are considerable inter-individual variations in drug kinetics, which may not be accounted for solely by genetic variation. Responses to pharmacotherapy are multifaceted and involve the interaction of environmental and... 

As shown in Figure 15.1, variations in the ethnic response to drugs are related to many interlinking factors. Genetic factors that control both pharmacokinetics and... 

Pharmacokinetic modeling, 208 Pharmacokinetics (PK), 99, 211 Pharmacologic agents, variation in response to, 43 Pharmacologic research, 31 Pharmacology, genetic variation and, 36-38... 

Whatever the scope of your investigations into selectivity, it is critical that you address the issue of product complexation in the sample, particularly com-plexation with metals. Complexation problems are by no means universal, but they are more common than generally realized. If you confirm the occurrence of product complexation, it is important to discover and characterize its source. Even though this may not fall strictly within the usual bounds of assay development responsibilities, the potential for the problem to affect purification, formulation, and even pharmacokinetics demands that this potential source of variation be addressed. Seek to eliminate it. If you cannot eliminate it, then reduce it. If you cannot reduce it, then at least try to maintain it within defined limits. 

Setting aside issues of compliance and administration errors, the therapeutic response experienced by each patient may be influenced by variations in pharmacokinetics (rate and extent of absorption, distribution, elimination) and pharmacodynamics (physiologic, pathologic, and genetic factors receptor interactions and tolerance). 

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