Statins are one of the most common medications dispensed in the US and are associated with clinically significant drug interactions. 1,2 The most common adverse drug reaction (ADR) of statin drug interactions is muscle-related toxicities. 2 Despite technology advances to alert clinicians to drug interactions, updated statin manufacturer labeling, and guideline recommendations, inappropriate prescribing and dispensing of statin drug interactions continues to occur in health care systems. 2-10
The medical literature has demonstrated many opportunities for pharmacists to prevent and mitigate drug interactions. At the points of prescribing and dispensing, pharmacists can reduce the number of potential drug interactions for the patient. 11-13 Pharmacists also have identified and resolved drug interactions through quality assurance review after dispensing to a patient. 7,8
Regardless of the time point of an intervention, the most common method pharmacists used to resolve drug interactions was through recommendations to a prescriber. The recommendations were generated through academic detailing, clinical decision support algorithms, drug conversions, or the pharmacist’s expertise. Regardless of the method the pharmacist used, the prescriber had the final authority to accept or decline the recommendation. 7,8,11-13 Although these interventions were effective, pharmacists could further streamline the process by autonomously resolving drug interactions. However, these types of interventions are not well described in the medical literature.
Background
The US Department of Veterans Affairs (VA) Veterans Integrated Service Network (VISN), established the Safety Target of Polypharmacy (STOP) report in 2015. At each facility in the network, the report identified patients who were dispensed medications known to have drug interactions. The interactions were chosen by the VISN, and the severity of the interactions was based on coding parameters within the VA computerized order entry system, which uses a severity score based on First Databank data. At the Harry S. Truman Memorial Veterans’ Hospital (Truman VA) in Columbia, Missouri, > 500 drug interactions were initially active on the STOP report. The most common drug interactions were statins with gemfibrozil and statins with niacin.1 4-18 The Truman VA Pharmacy Service was charged with resolving the interactions for the facility.
The Truman VA employs 3 Patient Aligned Care Team (PACT) Clinical Pharmacy Specialists (CPS) practicing within primary care clinics. PACT is the patientcentered medical home model used by the VA. PACT CPS are ambulatory care pharmacists who assist providers in managing diseases using a scope of practice. Having a scope of practice would have allowed the PACT CPS to manage drug interactions with independent prescribing authority. However, due to the high volume of STOP report interactions and limited PACT CPS resources, the Pharmacy Service needed to develop an efficient, patient-centered method to resolve them. The intervention also needed to allow pharmacists, both with and without a scope of practice, to address the interactions.
Methods
The Truman VA Pharmacy Service developed protocols, approved by the Pharmacy and Therapeutics (P&T) Committee, to manage the specific gemfibrozil-statin and niacinstatin interactions chosen for the VISN 15 STOP report (Figures 1 and 2). The protocols were designed to identify patients who did not have a clear indication for gemfibrozil or niacin, were likely to maintain triglycerides (TGs) < 500 mg/dL without these medications, and would not likely require close monitoring after discontinuation .19 The protocols allowed pharmacists to autonomously discontinue gemfibrozil or niacin if patients did not have a history of pancreatitis, TGs ≥ 400 mg/dL or a nonlipid indication for niacin (eg, pellagra) after establishing care at Truman VA. Additionally, both interacting medications had to be dispensed by the VA. When pharmacists discontinued a medication, it was documented in a note in the patient electronic health record. The prescriber was notified through the note and the patient received a notification letter. Follow-up laboratory monitoring was not required as part of the protocol.