Analysis of comprehensive pharmacogenomic profiling to impact in-hospital prescribing

In-hospital adverse medication events result in increased morbidity and mortality. Many implicated drugs carry pharmacogenomic information. We hypothesized that comprehensive pre-emptive pharmacogenomic profiling could have high relevance for in-hospital prescribing.

We retrospectively analyzed the in-hospital medications of a genotyped outpatient cohort admitted at our institution from 2012 to 2015. The endpoints were medication changes (new medications initiated, dose adjustments, or medications discontinued) involving drugs with pharmacogenomic annotations from three sources: Clinical Pharmacogenetics Implementation Consortium guidance, Food and Drug Administration label information, and drugs with clinical decision supports in our institutional pharmacogenomic Genomic Prescribing System.

Of 867 genotyped outpatients, 20 were hospitalized (mean: 78.2 years, 65% male). This hospitalized cohort was significantly older (78.2 vs. 61.3 years, P<0.0001) and took more medications (8.9 vs. 5.0 medications, P<0.0001). Out of 159 medication changes made, most (67.9%) were new medications (average: 2.5/hospitalization) with one-third of these having clinically annotated pharmacogenomic information. Half of all hospitalizations involved at least one pharmacogenomic medication. Over half (55%) of the hospitalized cohort was newly prescribed at least one of eight key pharmacogenomic medications, including high-risk drugs such as clopidogrel, codeine, and warfarin.

Our study suggested that older patients and those with polypharmacy were at increased risk for hospitalizations, where many new prescriptions included frequently used pharmacogenomic drugs. Targeting this group for pre-emptive genotyping would facilitate the delivery of highly relevant information to inform inpatient prescribing.