” However, this meta-analysis showed that there was a slight increase in stent thrombosis in a small group of patients who had a CYP2C19 loss-of-function allele. Another meta-analysis was conducted with slightly different inclusion criteria.

This meta-analysis included some cohort studies, retrospective studies, sub-studies, prospective case cohorts, and case control studies.18 The authors concluded that the gathered information from the genetic association studies did not indicate a substantial or consistent influence of CYP2C19 gene polymorphisms on Inhibitors,research,lifescience,medical the clinical efficacy of clopidogrel. Therefore, the current evidence does not support the use of individualized CYP2C19 genotyping. They did not even find a weak signal of elevated stent thrombosis in patients who had a CYP2C19 loss-of-function allele that was seen in the first meta-analysis. NEW

Inhibitors,research,lifescience,medical ANTI-CLOTTING THERAPY DRUGS The whole controversy about genetic testing is due to the fact that clopidogrel needs to be metabolized to become an active drug. However, new agents such as prasugrel, ticagrelor, and elinogrel do not undergo CYP2C19 metabolism. They are active, or almost active, drugs, and genetic variants do not appear to affect their metabolism. Therefore, instead of genotyping, we should prescribe a drug that works on all Inhibitors,research,lifescience,medical patients regardless of their genotype. The efficacy of these new drugs (prasugrel, ticagrelor, and elinogrel) as compared to clopidogrel was shown in a number of studies. One such study compared the efficacy of clopidogrel and prasugrel. The TRITON–TIMI 38 trial had 2,932 patients who were genotyped for the CYP2C19 Inhibitors,research,lifescience,medical and ABCB1 genes. Roughly half of the patients were treated with clopidogrel and the other half with prasugrel. The trial period was 15 months.19 When the genetic components of the patients were analyzed, Inhibitors,research,lifescience,medical it was found that when both ABCB1 and CYP2C19 are mutated, there is indeed a risk for major adverse events for patients who carry a double mutation and receive

clopidogrel. This effect was not seen on patients who received prasugrel. Ticagrelor (Figure 3) is an active drug that does not have to be metabolized. A trial was conducted in which ticagrelor was compared Endonuclease to clopidogrel (the PLATO trial).20 A total of 10,285 patients with acute coronary syndrome were genotyped for CYP2C19 and ABCB1 and then randomized to receive ticagrelor or clopidogrel. Ticagrelor was found to be more efficacious for acute coronary syndrome than clopidogrel, irrespective of CYP2C19 and ABCB1 polymorphisms. The researchers concluded that the “use of ticagrelor instead of clopidogrel eliminates the need for presently recommended genetic testing before dual antiplatelet treatment.” Figure 3 Chemical JSH23 composition of ticagrelor.