Pharmacogenomics in Critical Care

Scholarly literature on nurses and pharmacogenomics: A scoping review

BACKGROUND

Pharmacogenomics is the bioscience investigating how genes affect medication responses. Nurses are instrumental in medication safety. Pharmacogenomics is slowly being integrated into healthcare, and knowledge and understanding of it is now pertinent to nursing practice.

PURPOSE

This paper aims to map the scholarly literature on pharmacogenomics in relation to nurses.

METHODS

A scoping review was conducted in four databases: CINAHL, Embase (Ovid), ProQuest Health and Medicine and PubMed using the search terms pharmacogenomic*, pharmacogenetic*, PGx*, and nurs*, resulting in 263 articles of which 77 articles met the inclusion criteria.

FINDINGS

Most articles (85 %, n = 65) were non-empirical and 12 presented empirical data (15 %, n = 12). The articles were USA-centric (81 %, n = 62) and represented a broad range of nursing specialties.

CONCLUSION

The majority of scholarly literature on nurses and pharmacogenomics is narrative reviews. Further empirical research is warranted to investigate nurses' current knowledge levels and potential involvement with pharmacogenomics in clinical practice.

Pharmacogenetics in critical care: association between CYP3A5 rs776746 A/G genotype and acetaminophen response in sepsis and septic shock

BACKGROUND

Pharmacogenetics could represent a further resource to understand the interindividual heterogeneity of response of the host to sepsis and to provide a personalized approach to the critical care patient.

METHODS

Secondary analysis of data from the prospective observational study NCT02750163, in 50 adult septic and septic shock patients treated with Acetaminophen (ACT) for pyrexia. We investigated the presence of two polymorphisms, located respectively in the genes UGT1A1 and CYP3A5, that encode for proteins related to the hepatic metabolism of ACT. The main dependent variables explored were plasmatic concentration of ACT, body temperature and hepatic parameters.

RESULTS

8% of the patients carried CYP3A5 rs776746 A/G genotypes and showed significantly higher plasma levels of ACT than GG wild type patients, and than patients with UGT1A1 rs8330 C/G genotypes.

CONCLUSIONS

Identifying specific genotypes of response to ACT may be helpful to guide a more personalized titration of therapy in sepsis and septic shock. CYP3A5 might be a good biomarker for ACT metabolism; however further studies are needed to confirm this result.

TRIAL REGISTRATION

NCT02750163.

Description of Pharmacogenomic Testing Among Patients Admitted to the Intensive Care Unit After Cardiovascular Surgery

BACKGROUND

Pharmacogenomic (PGx) testing has the potential to provide information on specific drug-metabolizing enzymes that may lead to an absence, reduction, or increase in medication effect in patients. There is a paucity of prospective studies examining PGx testing in the intensive care unit (ICU) setting.

RESEARCH AIMS

To (1) obtain a PGx panel in a sample of cardiovascular (CV) surgical patients with a planned ICU stay and identify phenotypes, and (2) identify PGx variants that may inform treatment regimens and may warrant prescribing adjustments.

DESIGN AND METHODS

Descriptive, single cohort cross-sectional design. Adult (≥18 years) CV patients with an anticipated postoperative ICU stay were enrolled from a large Midwestern tertiary academic medical center. Eligible patients provided informed consent at the time of their CV clinic appointment; PGx testing was then ordered. Pharmacogenomic testing consisted of the Focused Pharmacogenomics panel which included 10 genes and 55 medications.

RESULTS

Of the 272 patients screened, 100 (68% male) patients completed PGx testing (mean age 66.2 ± 9.6 years, mean Acute Physiology, Age and Chronic Health Evaluation III score 76.1 ± standard deviation). Pharmacogenomic results were available in the medical record within a median of 52.4 hours (interquartile range: 33.4-80.3). Pharmacogenomic testing results identified 5 CYP2C19 poor metabolizers, 26 CYP2C19 rapid metabolizers, 5 CYP2C19 ultrarapid metabolizers, 6 CYP2D6 poor metabolizers, 5 CYP2D6 poor to intermediate metabolizers, and 2 CYP2D6 rapid metabolizers identified. Overall, 98% of patients had actionable or potentially actionable PGx results, including 82% for warfarin, 65% for propafenone, 65% for tramadol, 46% for oxycodone, 45% for metoprolol, 33% for clopidogrel, 32% for proton pump inhibitors, 25% for statins, and 12% for haloperidol.

CONCLUSIONS

A significant portion of patients had identified genetic variants that may warrant changes in medication management during and after CV-ICU stay. It remains to be seen if PGx testing leads to improvements in ICU patient outcomes.

Pharmacogenomics and Psychiatric Nursing

The treatment of mental illness is often done on a trial-and-error basis and achieving therapeutic benefits from a medication is not always guaranteed. Pharmacogenomics explores the role of gene-gene interactions and interindividual responses to a drug and may be promising in the guidance of pharmacotherapeutic options. In the present study, the impact of pharmacogenomic testing in management of mental health medication was investigated. Participants were identified at a local outpatient mental health facility through convenience sampling. Retrospective chart review included medication history, adverse drug reactions, pharmacogenomic history, and demographic data including insurance coverage. Chart review focused on six months pre- and post-pharmacogenomic for a comparison with the patient serving as their own control. Results indicate a high incidence of alterations in two specific cytochrome enzymes, CYP2D6 and CYP2C19. In total, 82% of the sample had variations with CYP2D6, while 64% of individuals had variations with CYP2C19. In total, 91% of patients tested received Medicaid or Medicare. Post-pharmacogenomic testing, all patient drug regimens were modified, and all reported less adverse side effects. Moreover, advanced practice nurse providers educated patients about the availability of genetic testing, initiated testing and provided care based on findings. These results demonstrate the utility of genetic testing in the realm of mental health. Future directions involve further exploring the benefits of pharmacogenomic testing in this vulnerable population.