Eva Pindurová

Serum dextromethorphan/dextrorphan metabolic ratio for CYP2D6 phenotyping in clinical practice

What is known and Objective:  Accurate prediction of actual CYP2D6 metabolic activity may prevent some adverse drug reactions and improve therapeutic response in patients receiving CYP2D6 substrates. Dextromethorphan‐to‐dextrorphan metabolic ratio (MRDEM/DOR) is well established as a marker of CYP2D6 metabolizer status. The relationship between urine and plasma or serum MRDEM/DOR is not well established nor is there evidence of antimode for separation of intermediate and especially poor metabolizers (PM) from extensive metabolizers (EM). This study addressed whether CYP2D6 phenotyping using molar metabolic ratio of dextromethorphan to dextrorphan (MRDEM/DOR) in serum is usable and reliable in clinical practice as urinary MRDEM/DOR.

MDR1 in Paroxetine-Induced Sexual Dysfunction

Paroxetine-induced sexual dysfunction represents a frequent treatment complication of otherwise efficient antidepressants. The genetic polymorphism of pharmacokinetic genes may contribute to the occurrence of such dysfunctions. This study presents the effect of MDR1 gene polymorphisms on sexual function in 18 women with bulimia nervosa, 18 women with anxiety disorders, and 19 healthy control subjects. It also deals with the relation between MDR1 gene polymorphisms and paroxetine-induced sexual dysfunction. The results demonstrated that MDR1 G2677T/A gene polymorphism allele carriers treated with paroxetine presented with difficulties with orgasm (p = .008) and lubrication (p < .001).