Cost-effectiveness of CYP2D6 and CYP2C19 Genotyping in Psychiatric Patients in Curacao

The cytochrome P450 (CYP) is a group of metabolic enzymes, from which the 2D6 and CYP2C19 polymorphisms are specifically related to the metabolism of psychiatric drugs. The prevalence of CYP2D6 and CYP2C19 polymorphisms differs among ethnicities. Depending on the number of functional alleles, individuals are classified as Poor Metabolizer (PM), Intermediate Metabolizer (IM), Extensive Metabolizer (EM) or Ultra Rapid Metabolizer (UM). Research has suggested that PM genotype is a predisposing factor for antipsychotic-induced side-effects. Besides susceptibility for side effects and lower quality of life, also, a relationship between phenotype and costs of care has been shown. Guidelines recommend that PM, IM and UM genotypes need dose adjustment, to optimize the effectiveness of the drug and/or to reduce side effects. No research has been done to investigate cost-effectiveness of implementation of genotyping in daily clinical psychiatric practice. This study investigates the effectiveness of implementation of CYP2D6 and CYP2C19 genotyping in psychiatric patients in Curacao and analyzes the costs of genotyping versus health benefits.