Pharmacogenomics and antihypertensive drugs: a path toward personalized medicine

Pharmacotherapeutic Follow-up and Pharmacogenetics of CYP2C9 and CYP3A4 in Antihypertensive Therapy: A Pilot Study in a Community Pharmacy

No pharmacogenetic studies have yet been conducted in community pharmacies, despite pharmacogenetics being an emerging discipline. Pharmacotherapeutic follow-up (PFU) was performed for 6 months in 37 patients receiving antihypertensive treatment, and they were genotyped for variant alleles *2 and *3 in the CYP2C9 gene and *1B in CYP3A4. Systolic blood pressure, cardiovascular risk, and adherence improved with PFU. Most of the interactions between drugs were represented by concurrent administration of statins and calcium channel blockers, which both use CYP3A4 for their metabolism. Heterozygotic patients for the CYP2C9*2 allele showed higher mean heart rate values after PFU than homozygous patients (73.4 ± 10.0 pulse/min vs 66.2 ± 10.6 pulse/min, respectively; P = .048). Carriers of CYP2C9*2 showed a tendency to less frequent negative outcomes associated with medication due to inefficacy than homozygous patients (50% vs 78.9%, respectively; P = .072). Pharmacogenetics and PFU can be used in community pharmacies to carry out a more exhaustive study of medication in hypertensive outpatients.

Interactions of renin–angiotensin system gene polymorphisms and antihypertensive effect of benazepril in Chinese population

Aim: Angiotensin-converting enzyme inhibitors are widely used antihypertensive drugs with individual response variation. We studied whether interactions of AGT, AGTR1 and ACE2 gene polymorphisms affect this response. Materials & methods: Our study is based on a 3-year field trial with 1831 hypertensive patients prescribed benazepril. Generalized multifactor dimensionality reduction was used to explore interaction models and logistic regressions were used to confirm them. Results: A two-locus model involving the AGT and ACE2 genes was found in males, the sensitive genotypes showed an odds ratio (OR) of 1.9 (95% CI: 1.3–2.8) when compared with nonsensitive genotypes. Two AGT–AGTR1 models were found in females, with an OR of 3.5 (95% CI: 2.0–5.9) and 3.1 (95% CI: 1.8–5.3). Conclusion: Gender-specific gene–gene interactions of the AGT, AGTR1 and ACE2 genes were associated with individual variation of response to benazepril. Further studies are needed to confirm this finding.

Original submitted 1 November 2010; Revision submitted 10 January 2011

Candidate gene microarray analysis in peripheral blood cells for studying hypertension/obesity

AIMS

The gene expression of 182 cardiovascular candidate genes was measured in high quality groups of individuals (n = 20) by microarrays to determine whether a subset of genes would discriminate obese and hypertensive individuals, in spite of the existence of a close link between these two cardiovascular risk factors.

MATERIALS & METHODS

The results were validated on the 20 subjects used for microarray analysis and on 62 additional individuals by real-time PCR.

RESULTS

The first analysis, where patient groups were compared with healthy subjects, revealed 15 out of 182 genes that differed in hypertensive, obese or obesity-related hypertensive individuals. These genes were ALOX5, APOA2, SELL, RGS2, CD14, FPR1, CAMP, DEFA3, DEFA4, CBS, CHRM1, ICAM1, NR1H2, SCNN1B and TGFB1. A second analysis was carried out in which patient groups were compared with each other, demonstrating FPR1 and DEFA3 as being significant genes discriminating patient groups. Furthermore, an analysis stratified by sex revealed that, with the exception of DEFA3, there are no other common genes between men and women.

DISCUSSION

We were able to indentify a number of interesting genes that distinguish patient and healthy subject groups as well as patient groups between them.

CONCLUSION

In addition, it seems that gender plays an important role, at least for some of the genes we tested. These findings may have important implications in the screening and etiology of hypertension or obesity, and could further help to focus on these specific mRNAs as antisense therapy targets.