Polymorphic 4-hydroxylation of debrisoquine in a Turkish population

Competing Benefits and Competing Hazards: The Benefit to Harm Balance in Individual Patients in Rational Therapeutics

For any therapeutic intervention in an individual, there is a balance between the potential benefits and the possible harms. The extent to which the benefits are desirable in a given condition depends on the efficacy of the intervention, the chance of obtaining it and the seriousness and intensity of the condition. The extent to which the harms are undesirable depends on the nature of the hazard that can lead to harm, the chance that the harm will occur and its seriousness and intensity. Rational therapeutic decisions require clinicians to consider competing courses of action, with potential benefits of different desirability and potential harms of different undesirability. They also have a duty to explain to the patient, for the contemplated interventions, both the possible benefits and the potential harms that the patient may consider significant. In an individual patient, it is necessary to consider (a) the probabilities of benefit from both intervention and non-intervention and (b) the probabilities of harm from both intervention and non-intervention. However, there are several potential problems. Here, we consider how failure to distinguish maximum benefits from probable benefits, or hazards (potential harms) from probable harms, and failure to consider all the competing probabilities may lead to imperfect therapeutic decisions. We also briefly discuss methods to assess the benefit to harm balance.

Bioinformatics Research on Inter-racial Difference in Drug Metabolism I. Analysis on Frequencies of Mutant Alleles and Poor Metabolizers on CYP2D6 and CYP2C19

The enzyme activities of CYP2D6 and CYP2C19 show a genetic polymorphism, and the frequency of poor metabolizers (PMs) on these enzymes depends on races. In the present study, the frequencies of mutant alleles and PMs in each race were analyzed based on information from published studies, considering the genetic polymorphisms of CYP2D6 and CYP2C19 as the causal factors of racial and inter-individual differences in pharmacokinetics. As a result, it was shown that there were racial differences in the frequencies of each mutant allele and PMs. The frequencies of PMs on CYP2D6 are 1.9% of Asians and 7.7% of Caucasians, and those of PMs on CYP2C19 are 15.8% of Asians and 2.2% of Caucasians. Based on the results, it was suggested that there would be racial differences in the frequencies of PM subjects whose blood concentrations might be higher for drugs metabolized by these enzymes. Additionally, it was suggested that enzyme activities would vary according to the number of functional alleles even in subjects judged to be extensive metabolizers (EMs). In the bridging study, genetic information regarding CYP2D6 and CYP2C19 of the subjects will help extrapolate foreign clinical data to a domestic population.