Trends in Opioid Prescribing and Dispensing by Veterinarians in Pennsylvania

Key Points Question What kind of opioids and how many are prescribed by veterinarians? Findings In this cross-sectional inventory study of opioid prescribing by 134 veterinarians in a multidisciplinary acute care veterinary teaching hospital in Pennsylvania, a parallel trend of escalating opioid prescriptions and potency was found from 2007 through 2017. The substantial and increasing volume of opioids prescribed highlights analogous concerns about excessive opioid prescribing in humans. Meaning Veterinarians prescribe a substantial amount of opioids, so prescribing practices of veterinarians merit further evaluation to safeguard public health.


Introduction
The United States is in the midst of an opioid crisis that has expanded from oral prescribed opioids to include heroin and highly lethal fentanyl analogues. Approximately 4 of 5 people who use heroin previously used prescription drugs. 1 A major factor contributing to this epidemic is the overall increase in the ready availability of opioids. Patients with a history of opioid use disorder reported obtaining their opioids primarily for free from a friend or relative or from a physician. 2 Although medical and dental health care professionals have been the major source of these opioids, the contribution of veterinary prescribing has not been quantitatively assessed.
Veterinarians and veterinary hospitals can be registered with the US Drug Enforcement Administration and in many states can administer, prescribe, stock, and dispense opioids, often without a reporting requirement to the state's Prescription Drug Monitoring Program (PDMP). 3 This situation may create a pathway that allows humans to covertly access opioids for diversion or misuse from their pets or other animals. In addition, leftover opioids from veterinary prescriptions can also result in diversion, misuse, abuse, or inadvertent toddler exposure. We investigated the potential volume of various opioids available through veterinary sources by inventorying the controlled substance records of a single veterinary hospital during an 11-year period that paralleled the rise of the opioid crisis.

Methods
This cross-sectional study inventoried all opioid tablets and/or patches dispensed or prescribed by Prescribing data were obtained by reviewing detailed, controlled substance pharmacy records in a single acute care veterinary referral hospital with 36 347 annual visits in fiscal year 2018 to describe trends in opioid prescribing and dispensing. Three of the most frequently used opioids (hydrocodone bitartrate, tramadol hydrochloride, and codeine sulfate) were tabulated, and fentanyl citrate was dispensed in patch form. All tablet strengths were included, and each opioid tablet was converted into morphine milligram equivalent (MME) amounts using standard conversion formulas. 4 Only solid forms (pills and patches) were included; liquid formulations were omitted.
We used the Pennsylvania state veterinary opioid prescribing data in the US Drug Enforcement Administration Automation of Reports and Consolidated Orders System (ARCOS) for 2014 through 2017 to assess the magnitude of overall veterinary opioid prescribing in Pennsylvania and to compare the relative frequency and veterinary use of each opioid on a statewide level. 5 However, tramadol (a Schedule IV drug) prescribing information was not available in ARCOS because only Schedule II and III drugs were included. Descriptive statistics were used.

Results
In this acute care multidisciplinary veterinary hospital, any licensed veterinarian (intern, resident, or   Although extensive efforts have been made in educational campaigns about opioid misuse directed toward physicians and dentists, similar programs have not been replicated for veterinarians.

Figure. Changes in Opioid Dispensing and Prescribing in Tablet and Patch Forms and Morphine Milligram Equivalents (MMEs) During the Study Period
The recent increased scrutiny of medical and dental opioid prescribing may have redirected some individuals to obtain opioids from veterinarians. 8 In a recent survey, 9 73% of veterinarians reported little education about opioid misuse in their training. This lack of awareness may have led to an increased vulnerability to such fraud. 9 Concerns about diversion and misuse are now being addressed among this latter group. 10 In addition, the extensive use of opioids may leave unused pills in homes with pets, raising the risk for exploratory diversion by teenagers or unintentional exposure in toddlers.
Regulatory oversight and prescriber educational efforts analogous to those in medicine are needed in veterinary practice. Despite mandatory reporting to the PDMP for scheduled drugs for human use, only 20 states mandate that veterinarians report their opioid prescribing. 3 Although logistically complicated to enact, a requirement to access the PDMP may provide valuable information for veterinarians and other health care professionals as well. Further exploration is warranted to examine opportunities to manage veterinary opioid prescribing to mitigate human consequences.