Additional Testing Could Prevent Adverse Drug Events

Adverse drug reactions can cause poor patient outcomes and increased costs related to healthcare utilization.

Certain populations are more at risk for adverse drug reactions. Specifically, older patients are more susceptible to adverse drug reactions (ADRs) because of comorbidities, cognitive and functional impairment, polypharmacy, and changes in pharmacokinetics and pharmacodynamics.

Previous studies have found that ADR-related hospital admissions accounted for 6% to 12% of all admissions for older people. Although some ADR-related hospitalizations are unavoidable, the researchers state that over half are preventable.

In a study published by the British Journal of Pharmacology, investigators reviewed 1000 patients that had an unplanned admission to a tertiary hospital. Approximately 12.4% of patients admitted had a present adverse drug reaction, and 8.1% of patients had an adverse drug reaction that caused hospitalization.

The investigators discovered that the most common adverse drug reaction among patients admitted to the hospital was gastrointestinal-related. Cardiovascular drugs were the most common category to cause hospitalization from the reaction, according to the study.

Hospitalization due to adverse drug reactions also increased healthcare costs due to increased lengths of stay compared with patients who did not have a reaction (4 days versus 3 days).

Investigators said that some of the adverse drug reactions (ADR) could have been predicted based on patient genetics. Approximately 30% of ADRs during admission were caused by 1 or more drugs with a clinical annotation in the Pharmacogenomics KnowldgeBase, according to the study.

Pharmacogenetic testing could have potentially prevented adverse events in these patients.

“This study is important because we have quantified the burden of clinically impactful ADRs in the general adult population in Singapore for the very first time,” said co-senior author of the study Alexandre Chan, PharmD, MPH, FCCP, BCPS, BCOP. “Furthermore, results of this study provide essential directions to future pharmacogenomic research for reduction of ADR-related hospitalizations in Singapore.”