This article was written by Katie Meyer, PharmD, BCPS, BCGP
Adverse drug events (ADEs) cause approximately 6% of hospital admissions in the general population.1 In older patients with multiple comorbidities, this figure increases to approximately 23%.2 The prevalence of drug-drug interactions in older adults taking 5 or more medications has been estimated to be more than 80%.3 Proper identification of drug-drug interactions that may have contributed to the hospitalization is essential upon admission. The complexity of these scenarios has been previously reviewed.
Medication reconciliation and assessment upon admission is only one small step in ensuring drug safety. ADEs may—and do–occur at any time during a patient’s hospital stay. Formulary restrictions, route of administration changes, and medication changes and additions are frequent, and medication management during transitions of care are particularly problematic. Hospital pharmacists are trusted medication experts who can play an essential role in ensuring patient safety throughout a hospital stay, and the tools for them to do so are becoming ever more efficient and effective.
In addition to traditional one-drug to one-drug interaction systems that have been in use for 5 decades, new systems are becoming available that supports pharmacists’ recommendations with evidence, which includes scientific data relating to accumulative multi-drug simultaneous interactions and data from the FDA Adverse Event Reporting System. Because 80% of medications are metabolized by one system in the body, decision support technology like this can be critical for ensuring medication safety in real-time for patients with polypharmacy. Such tools empower pharmacists to more easily and rapidly identify and prioritize interactions and potential ADEs during the initial medication reconciliation and throughout the hospital stay and discharge process. Moreover, these tools help pharmacists optimize medication regimens, reduce risk for ADE-prolonged length-of-stay, and prevent future medication-related problems.
Intravenous (IV) medication safety tools are evolving as well. Many IV agents, including vancomycin and aminoglycoside antibiotics, have a narrow therapeutic index, making dosing complex and pharmacokinetic-guided. This means that even small differences in dosing or blood concentration can lead to ADEs or therapeutic failure; dosing must be precise for optimal medication efficacy and safety. Traditional trough-based pharmacokinetic models are cumbersome and require critical timing of blood retrieval, which is often difficult to obtain during a patient’s hospital stay. Now, however, hospital pharmacists can use decision-support systems to efficiently predict IV medication dosing based on population pharmacokinetic data. Such technology eliminates the burden of time-sensitive blood draws and also reduces risk for acute kidney injury due to improper dosing.
When circumstances allow for pharmacists to participate in the discharge process, technology such as the aforementioned decision-support tools are invaluable. Discharge planning often involves medication changes, including critical intravenous to oral conversions. Pharmacist intervention at this time can prevent new multi-drug interactions that may precipitate ADEs. When an IV medication is converted to oral therapy, hepatic enzymes become involved in drug metabolism and the probability of multi-drug, simultaneous interactions changes. For example, while IV fluconazole has little/no impact on metabolism of many other medications, oral fluconazole (as a potent inhibitor of CYP3A4, CYP2C19 and CYP2C9) interacts with various medications, including anticoagulants like warfarin, and can cause increased concentrations of drugs metabolized through the same enzymatic pathways. The new technologies discussed in this article can help pharmacists more easily recognize potential problems like this and more quickly adjust doses, so that ADEs can be prevented.
Studies repeatedly show that pharmacist intervention decreases medication-related problems and increases patient safety. Nevertheless, involving pharmacists who lack the appropriate tools can be time-consuming. As a general rule, resource allocation should be maximized by prioritizing pharmacist-led medication reconciliation and escalated medication safety services for those patients who are most likely to benefit. 5
In summary, throughout a patient’s hospital stay, there is real potential for medication-related problems and ADEs leading to increased patient morbidity and mortality and to increased healthcare costs. Identifying and mitigating this risk is vital for patient safety, and providing pharmacists with the sophisticated tools that allow them to better deliver care is imperative.
While there are a number of technologies today to help hospital pharmacists better and more efficiently promote patient safety, the ones specifically referenced in this article and the ones with which this author is most familiar are Tabula Rasa HealthCare’s MedWise (housing the Medication Risk Mitigation Matrix) for accumulative multi-drug interactions and DoseMeRx for IV dosing. Integration of these medication decision support tools into hospital pharmacy systems and into electronic health records better equips clinicians to identify, intervene, and prevent medication-related problems before they occur.
1. Poudel DR, Acharya P, Ghimire S, Dhital R, Bharati R. Burden of hospitalizations related to adverse drug events in the USA: a retrospective analysis from large inpatient database [published online February 24, 2017]. Pharmacoepidimeiol Drug Saf. doi: 10.1002/pds.4184 .
2. Laatikainene O, Sneck S, Bloigu R, Lahtinen M, Lauri T, Turpeinen M. Hospitalizations Due to Adverse Drug Events in the Elderly-A Retrospective Register Study [published online October 5, 2016]. Front Pharmacol. doi: 10.3389/fphar.2016.00358.
3. Doan J, Zakrzewski-Jakubiak H, Roy J, Turgeon J, Tannenbaum C. Prevalence and risk of potential cytochrome P450-mediated drug-drug interactions in older hospitalized patients with polypharmacy [published online March 12, 2013]. Ann Pharmacother. doi: 10.1345/aph.1R621.
4. Mallet L, Spinewine A, Huang A. The challenge of managing drug interactions in elderly people [published online July 14, 2007]. Lancet. doi: 10.1016/S0140-6736(07)61092-7.
5. Filippone EJ, Kraft WK, Farber JL. The Nephrotoxicity of Vancomycin [published online June 5, 2017]. Clin Pharmacol Ther. doi: 10.1002/cpt.726.
6. Morath B, Mayer T, Send AFJ, Hoppe-Tichy T, Haefeli WE, Seidling HM. Risk factors of adverse health outcomes after hospital discharge modifiable by clinical pharmacist interventions: a review with a systematic approach [published online June 14, 2017]. Br J Clin Pharmacol. doi: 10.1111/bcp.13318.