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

Results

Seventy-five patients were included in this review. The average age of patients was 66 years; and 12% were female (n = 9) (Table 2). The largest number of consults came from PCPs (44%, n = 33) and the pain clinic (43%, n = 32). Nearly half (48%) of the consultations were for opioid tapering (n = 36), followed by 37% for opioid optimization or monitoring (n = 28), and 19% for nonopioid optimization (n = 14). The most common primary diagnoses at consultation were for chronic low back pain (56%), chronic neck pain (20%), and osteoarthritis (16%).

The average MME at time of consult was 93 MME compared with 31 MME at discharge which was statisticially significant (P < .01) (Figure 1). The mean percent change in MME was 46%, including methadone and 42% excluding methadone. There was a 26% change in UDS, 28% change in informed consent, 85% change in PDMP, 194% change in naloxone, and 357% change in STORM reviews from baseline to discharge with all demonstrating statistical significance (P < .01) (Figure 2). At discharge, the most common opioid prescribed was morphine SA (short acting) (n = 10, 13%, 44 average MME) and oxycodone/acetaminophen (n = 10, 13%, 28 average MME) (Table 3).

The average number of days from consult to initial visit was 23 days (Table 4). Face-to-face was the primary means of initial visit with 92% (n = 69) of visits, but phone was the primary mode of follow-up with 73% of visits (n = 55). The average number of follow-up visits was 7, representing 176 average days of time in the Pharmacy Pain Clinic. Consultation to the behavioral health performance program was the most common referral (n = 13, 17%).

Five patients were new opioid starts in the Pharmacy Pain Clinic. Two patients were on tramadol at time of consult. Of the 5 new opioid starts, 3 patients received oxycodone/acetaminophen, 1 received buprenorphine patch, and 1 received hydrocodone/acetaminophen. The new opioid start average was 25 MME. All 5 patients had a UDS for opioid risk mitigation, 4 used consent and STORM reviews, and 2 patients had PDMP checks and naloxone.

Discussion

There was a statistically significant decrease of the mean MME between the time of consult and the time of discharge. There also were statistically significant changes in use of opioid risk mitigation strategies. Since methadone has a high MME, the mean reduction of MME was calculated with methadone (46%) and without methadone (42%). These data are consistent with other published studies examining opioid tapers in the VA population. Harden and colleagues calculated a 46% mean reduction in MME over 12 months for 72 veterans from opioid tapers implemented by PCPs, pain service, or pharmacist-run clinics.¹⁹

There is controversy about equianalgesic doses and no established universal equianalgesic conversion calculator or dose. Numerous equianalgesic opioid dose calculators are available, but for this analysis the CDC MME conversion factors were used (available at: https://www.cdc.gov/drugoverdose/pdf/calculating_total_daily_dose-a.pdf). Previous literature compared existing calculators and found significant variances in calculated doses for methadone and fentanyl conversions.²⁰ Additionally, there have been concerns expressed with the safety of the CDC opioid calculator specifically surrounding the conversions for methadone and tapentadol.²¹ In the end, I chose the CDC calculator because it is established, readily available, and consistent.

Pharmacists in pain management can address access issues.^2,3,11,12 The average length of time from consult to initial visit was 23 days. Often patients may have seen a HCP who implemented a change at the time of consult and wanted the patient to be seen 1 month later. Many patients at the HSTMVH live far from the facility, making in-person visits difficult. A majority of the follow-up visits were conducted by telephone. Patients were offered all modalities available for follow-up, including telephone, in-person, or telemedicine, but patients most often picked telephone. Patients averaged 7 follow-up visits before discharge. This number of visits would have taken time from other health care team members who could have been addressing other veterans. Patients were seen in clinic for 176 days on average, which supports and follows recommendations for a slow, incremental taper.

The opioid medications prescribed changed over time in the clinic. Methadone prescriptions dropped from 20 to 6 at consult to discharge, and fentanyl prescriptions fell from 7 to 2, respectively. The CDC guideline suggests use of long-acting products with more predictable pharmacokinetics (eg, morphine SA or oxycodone SA) rather than fentanyl or methadone.¹⁵ Notably, the use of buprenorphine products with FDA approval for pain indications increased from consult to discharge. Many of the patients in this study had pulmonary comorbidities, placing them at higher risk for adverse outcomes. Buprenorphine is a partial μ-opioid receptor agonist with a ceiling on respiratory depression so is potentially less risky in those with pulmonary comorbidities.

The biggest changes in opioid risk mitigation occurred in PDMP, OEND program, and STORM reviews. An 85% increase in PDMP reviews occurred with referral to the clinic. Missouri is the only state without a state-run PDMP. However, the St. Louis County PDMP was developed based on city or county participation and encompasses 85% of the population of Missouri and 94% of HCPs in Missouri as of August 29, 2019.²² Because there is no state-level PDMP, a review of the St. Louis County PDMP was not required during the review period. Nevertheless, the Pharmacy Pain Clinic uses the St. Louis County PDMP at the initial visit and regularly during care. VA policy requires a specific note title be used to document each check of the PDMP.²³

There was a 194% increase in patients receiving naloxone with consultation to the Pharmacy Pain Clinic. Due to low coprescribing of naloxone for patients prescribed chronic opioid therapy, The author led an interdisciplinary team analysis of health care failure mode effects during the study period. This led to a process change with coprescribing of naloxone at refill in the primary care clinic.

The Comprehensive Addiction and Recovery Act of 2016 mandated that the VA review STORM on new start of opioids or patient identified as “very high-opioid prescription risk” category by an interdisciplinary opioid risk review team.²⁴ Thus many of the patients referred to clinic didn’t require STORM reviews since they were not new opioid starts or identified as high risk. However, in the standard review of all new patients to the Pharmacy Pain Clinic, a STORM review is conducted and documented to assess the patient’s level of risk.

Only 5 patients were started on opioid medications during the study period. This is consistent with both CDC and the joint VA/US Department of Defense opioid prescribing guidelines that recommend against initiation of opioids for chronic nonmalignant pain.^13,15 Two of the patients were prescribed tramadol for ineffective pain control at time of consult. Furthermore, 4 of the 5 patients were started on a short-acting opioid, which was supported by guidelines.^13,15 One patient was initiated on buprenorphine patches due to comorbid chronic kidney disease. The VA does not limit the quantity of new opioid prescriptions, although some states and private insurance plans are implementing limitations. Guidelines also recommend against exceeding 90 MME due to risk. The average MME in this project at discharge was 25 MME. Use of opioid risk mitigation for the new opioid starts was reasonable. The reason for the missing PDMP report is unknown based on chart review and atypical according to clinic practice.

Recently, efforts to expand pharmacist training and positions in pain management at VA facilities have been undertaken. In 2016, there were just 11 American Society of Health-System Pharmacists-accredited pharmacy postgraduate year 2 pain and palliative care residency programs, which has expanded to 26 sites in 2020.^2,3,25 In addition, the Clinical Pharmacy Practice Office and the VA Office of Rural Health have helped to hire 33 new pain management pharmacists.³

The role of pharmacists in prescribing controlled substances is limited mainly due to the small number of states that extend this authority.⁷ At the VA, a pharmacist can practice using any state of licensure. Therefore, a pharmacist working at a VA in a state that does not authorize controlled substance prescribing could obtain a license in a state that does permit it. However, the main barrier to obtaining other state licensures is the cost. At the time the author obtained controlled substance prescriptive authority, little direction was available on the process for advanced practice pharmacists at the VA. Since then, guidance has been developed to ease this process. Educational endeavors at VA have been implemented with the intent to increase the number of pharmacists with controlled substance prescriptive authority.

Barriers to pharmacists providing pain care extend beyond limited controlled substance prescriptive authority. Often pharmacists are still viewed in their traditional and operational role.^9,10 Other health care team members and patients may not be aware or familiar with the training, knowledge, and skills of pharmacist's and their suitability as an APP.^26,27 Most states permit pharmacists in establishing CDTA but not all. Additionally, some states recognize pharmacists as HCPs but many more do not. Furthermore, the Social Security Act does not include pharmacists as HCPs. This makes it challenging, though not impossible, for pharmacists to bill for their services.³