Effect of personality type on pharmacodynamics through changing pharmacokinetics

Perturbation of mitiglinide metabolism by chronic unpredicted mild stress in rats

Many diabetic patients complicated with wild to severe depression. It is unclear in diabetic medication whether depression perturbs the drug metabolic process of the hypoglycemic agents or not. The present study was designed to investigate the impact of chronic unpredicted mild stress (CUMS) -induced depression on mitiglinide (MGN) pharmacokinetics in rats. Adult female Sprague-Dawley rats in CUMS group were subjected to different types of stressors and the stress procedures lasted for 8 weeks. Control group without receiving stress had free access to food and water. Open-field test and 5-HT levels were assayed to evaluate the depression. After CUMS all rats were given 2.5 mg/kg of mitiglinide per os. The blood samples were collected at different time and mitiglinide plasma concentration was measured by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Non-compartmental statistical moment analysis was processed with DAS software. In CMUS-induced depression group, peak concentration (Cmax), peak time (Tmax), area under curve (AUC0 → ∞), mean residence time (MRT0 → ∞), and half-life (T1/2z) were reduced while total plasma clearance (CLz/F) was increased compared to control group. These preliminary results indicated that CUMS-induced depression alter the drug metabolic process of mitiglinide in rats. This finding will be significant in clinic.

Relation between CYP2D6 phenotype and genotype and personality in healthy volunteers

Objectives: Our group has previously show that interindividual variability in CYP2D6 hydroxylation capacity was related to personality differences in cognitive social anxiety. Thus, we aimed to analyze whether this relationship between personality and CYP2D6 phenotype and genotype was found in a similar population of healthy volunteers from a different latitude and culture by using the same methodology. Methods: A total of 253 university students and staff from Havana Psychiatric Hospital and Calixto García Medical School in Cuba completed the Karolinska Scales of Personality (KSP), and were evaluated on debrisoquine hydroxylation capacity and CYP2D6 genotypes. KSP scores were compared between four groups, divided according to their CYP2D6 metabolic capacity: one of poor and three of extensive metabolizers. Furthermore, KSP scores were compared between another four different groups divided according to their number of CYP2D6 active genes: zero, one, two, and more than two. Results: In Cubans, the differences in cognitive social anxiety-related personality traits across the four CYP2D6 hydroxylation capacity groups were strikingly similar to those found in Spaniards. These differences also came out to be significant for psychic anxiety (p = 0.02) and socialization (p = 0.02). The same pattern of results obtained for the subscales of psychic anxiety, socialization, psychasthenia and inhibition of aggression with regard to phenotype in both the Cuban and Spanish studies were seen with regard to CYP2D6 genotypes. Conclusions: Corroborating these results further strengthens evidence of the relationship between CYP2D6 metabolic capacity and personality. In this population of healthy Cuban volunteers, the CYP2D6 hydroxylation capacity was related to the degree of anxiety and socialization. These results support the postulated reduction of serotonin in CYP2D6 poor metabolizers, which may be associated with a cluster of behavioral traits (e.g., anxiety, impulsivity). Thus, research is warranted to determine CYP2D6 functional implications for interindividual differences in vulnerability to neuropsychiatric diseases and drug response.