Retrospective Chart Review of Advanced Practice Pharmacist Prescribing of Controlled Substances for Pain Management at the Harry S. Truman Memorial Veterans’ Hospital

Study Aims

A review of the literature indicated sparse data on the impact of a pharmacist on opioid tapering, opioid dose, and opioid risk mitigation when the pharmacist is prescribing controlled substances. The purpose of this retrospective review was to characterize the controlled substance prescribing practices by the pharmacy pain clinic. The aim was to examine the pharmacist impact on morphine milligram equivalent (MME) and compliance with opioid risk mitigation strategies.

Methods

This project was a retrospective, single-center, chart review. The project was reviewed and approved by the University of Missouri-Columbia Institutional Review Board used by the Harry S. Truman Memorial Veterans’ Hospital (HSTMVH) as a quality improvement project. The author applied for controlled substance registration through the DEA and was issued registration April 30, 2018. The State of Ohio Board of Pharmacy was contacted as required by Ohio Administrative Code. The author's updated SOP to allow controlled substance prescribing was approved July 23, 2018. The CPS functions as an APP within an interdisciplinary pain management team that includes physicians, occupational and physical therapists, complementary and integrative health, and a psychologist. The reason for Pharmacy Pain Consult is required and it is primarily submitted through the electronic health record. The consult is reviewed for appropriateness and once approved is scheduled by support staff. Once the patient is stabilized, the patient is discharged back to their primary care provider (PCP) or referring provider for continued care. Patients were considered stabilized when their patient-specific goals were met, which varied from use of the lowest effective opioid dose to taper to discontinuation of opioids with no further medication changes needed. The taper strategy for each patient was individualized. Patients were generally tapered on their existing opioid medication unless they were new to the VA and on nonformulary medications or experiencing a significant adverse reaction. Numerous references are available through VA to assist with opioid tapering.^13,14 The CPS is able to refer patients to other services, including behavioral health for substance use disorder treatment and medication-assisted treatment if concerns were identified.

Initial data were collected from the Veterans Integrated Service Network (VISN) 15 Corporate Data Warehouse by the VISN pharmacy analytics program manager. The original report included patients prescribed a Schedule II to V controlled substance by the author from July 1, 2018 to January 31, 2020. Chart review was conducted on each patient to obtain additional data. At the time of consult and discharge the following data were collected: opioid medication; MME; use of opioid risk mitigation strategies, such as urine drug screens (UDS), informed consent, opioid overdose education and naloxone distribution program (OEND), risk assessment via stratification tool for opioid risk mitigation (STORM), PDMP checks; and nonopioid medication number and classes.

Patients were included in the review if they were prescribed an opioid Schedule II or III controlled substance between July 1, 2018 and January 31, 2020. Patient were excluded if they were prescribed an opioid Schedule II or III controlled substance primarily as coverage for another prescriber. Patients prescribed only pregabalin, tramadol, or a benzodiazepine also were excluded.

The primary endpoint was change in MME from baseline to discharge from clinic. Secondary endpoints included change in opioid risk mitigation strategies and change in opioid medications prescribed from baseline to discharge.

Descriptive statistics were used to analyze parts of the data. A 2-sided t test was used to compare baseline and discharge MME. The Fisher exact test was used to compare nominal data of opioid risk mitigation strategies.

Calculation of MME was performed using the conversion factors provided by the Centers Disease Control and Prevention (CDC) for opioid guideline.¹⁵ For buprenorphine, tapentadol, and levorphanol conversion ratios were obtained from other sources. The conversion ratios used, included 75:1 for oral morphine to transdermal buprenorphine, 1:3.3 for oral morphine to oral tapentadol, and 1:7.5 for oral levorphanol to oral morphine.^16,17 The Revised Standards for Quality Improvement Reporting Excellence (SQUIRE 2.0) was used to write the manuscript.¹⁸