Assessing Illinois companion animal veterinarians' antimicrobial prescription practices and the factors that influence their decisions when treating bacterial infections in dogs and cats.

AIMS: Judicious antimicrobial use in companion animal practice is critical for maintaining the effectiveness of antimicrobial agents against bacterial infections and reducing the selection of antimicrobial-resistant bacteria. This study aimed to provide insights into companion animal veterinarians' antimicrobial treatment recommendations for common bacterial infections in dogs and cats and describe the factors influencing their prescription choices. METHODS AND RESULTS: An online survey using QualtricsXM® software was administered between September and November 2022 to companion animal veterinarians who were Illinois State Veterinary Medical Association members. Descriptive and text analyses were conducted to assess the participants' responses. A total of 78 surveys were included in the analysis. Skin infections were ranked as the most common bacterial infections for which veterinarians prescribed antimicrobial agents, followed by ear, urinary tract, respiratory, and enteric infections. The severity of clinical symptoms and the results of bacterial culture and susceptibility tests were the most influential factors for veterinarians when making antimicrobial prescription choices. Veterinarians were aware of the current antimicrobial prescription guideline recommendations when prescribing antimicrobials empirically to nine hypothetical scenarios of bacterial infections. According to the results of the text analysis that assessed veterinarians' responses to an open-ended question, regarding their challenges when prescribing antimicrobial agents, the pairwise correlation of word frequencies within each response showed the highest correlations between the words 'owner' and 'compliance', 'administration' and 'route', 'cost' and 'culture', and 'patients' and 'acceptance'. CONCLUSIONS: The study results can support animal health stakeholders in the development of antimicrobial stewardship programmes to promote appropriate antimicrobial use and limit the emergence of antimicrobial resistance.

ABCG2 Polymorphisms and Predictive Fluoroquinolone Phototoxicity in Nondomestic Felids.

Fluoroquinolones are a widely used class of chemotherapeutics within veterinary medicine, prized for their broad-spectrum bactericidal activity. These drugs present a known risk of retinal phototoxicity in domestic cats (Felis catus); therefore, using lower doses and alternative antibiotic classes is encouraged in this species. This adverse drug effect of fluoroquinolones, and enrofloxacin specifically, has been determined to be species-specific in domestic felids. Four feline-specific missense variants in ABCG2 result in four amino acid changes (E159M, S279L, H283Q, and T644I) that are unique to the domestic cat compared with multiple other nonfeline mammalian species. These changes alter the ABCG2 protein involved with the cellular transmembrane transport of drugs, including fluoroquinolones, making the protein functionally defective in domestic cats. The predisposition to fluoroquinolone-mediated phototoxicity in nondomestic felids was explored in this study. At least eight nondomestic felids share the four ABCG2 missense variants with domestic cats, and eleven other felids shared at least three of the four domestic cat variants. Taken together, these results suggest the genetic potential for nondomestic felids to also experience fluoroquinolone-induced retinal phototoxicity; therefore, cautions similar to those for domestic cats should be followed for these drugs in the entire feline taxon.

Assessment of the physical compatibility of injectable enrofloxacin with commonly used intravenous fluids and drugs during simulated Y-port administration.

OBJECTIVE: To evaluate physical compatibility of small animal (SAE) and large animal (LAE) injectable formulations of enrofloxacin with select IV fluids and drugs. SAMPLE: 162 admixtures containing SAE or LAE with saline (0.9% NaCl) solution, lactated Ringer solution (LRS), Plasma-Lyte A (PLA), 6% hydroxyethylstarch 130/0.4 (HES), metoclopramide, or ampicillin-sulbactam. PROCEDURES: In the first of 2 simultaneously conducted experiments, admixtures containing enrofloxacin (10 mg/kg) and a volume of IV fluid that would be administered over a 20-minute period when dosed at the maintenance infusion rate (40 mL/kg/d for saline solution, LRS, and PLA and 20 mL/kg/d for HES) were created. In the second experiment, enrofloxacin (10 mg/kg) was admixed with saline solution (40 mL/kg/d) and metoclopramide (2 mg/kg/d) or ampicillin-sulbactam (30 mg/kg). In both experiments, admixture components were infused into a flask over 20 minutes assuming patient weights of 5, 10, and 20 kg. Admixtures were created by use of undiluted SAE and SAE diluted 1:1 with saline solution and undiluted LAE and LAE diluted 1:1 and 1:10 with saline solution. Admixtures were assessed for physical incompatibility at 0, 15, 30, and 60 minutes after completion of mixing. Physical incompatibility was defined as gross precipitation, cloudiness, Tyndall effect, or change in turbidity. RESULTS: Admixtures containing undiluted SAE or LAE were physically incompatible with saline solution, PLA, LRS, and HES. Because saline solution was used to dilute SAE and LAE, all admixtures containing diluted SAE or LAE were also physically incompatible. Physical compatibility of enrofloxacin with metoclopramide or ampicillin-sulbactam could not be assessed because those admixtures also contained saline solution. CONCLUSIONS AND CLINICAL RELEVANCE: Enrofloxacin was physically incompatible with all tested solutions.

The Current Landscape of Veterinary Compounding in the Veterinary Setting.

Compounding for veterinarians is regulated by the U.S. Food and Drug Administration, but day-to-day regulation is deferred to the state authorities. Veterinarians must meet certain standards when prescribing or dispensing a compounded medication. Veterinarians are expected to maintain current knowledge of the benefit of compounded preparations and prescribe and dispense in keeping with the best evidence related to animal and human health. Whether veterinarians recognize or adhere to these standards is unknown. A self-administered survey was distributed electronically to 30,000 email addresses on record with the Veterinary International Network. The survey asked questions about the regulations and standards associated with the use of or prescription of compounded medications. Of the distributed surveys, 1,520 survey responses were received, for a 5.1% response rate. All surveys were included in the final analysis. Respondents with a higher training level in compounding had a greater perceived skill level regarding compounding of medications (r = 0.26, P<0.0001). Similarly, respondents with a higher training level had a greater knowledge of state laws and regulations (r = 0.14, P<0.0001). Those with formal training had better scores on the assessment questions than those with informal or no training (P=0.01). Approximately one-third of the respondents felt that they were not knowledgeable at all about compounding rules and regulations. The most common compounded medications used in practice by veterinarians are methimazole, metronidazole, and doxycycline. Veterinarians mostly recognized that compounding backordered, commercially available products is permitted. Formal training improves familiarity with compounding rules, regulations, and current practices. Therefore, efforts should be directed at improving veterinary knowledge of laws and regulations surrounding the practice of compounding medications.

The Current Landscape of Veterinary Compounding in the Pharmacy Setting.

Medicating animals poses unique challenges that are often best dealt with via compounding. Pharmacists receive compounding training while in pharmacy school, but this training is not veterinary specific. Pharmacists are expected to have enough knowledge to properly verify prescriptions that are received at their practice site while keeping with the most up-to-date guidelines related to animal and human health. Whether pharmacists have the proper training to verify and/or compound veterinary specific medications is unknown. A self-administered survey was distributed electronically to 4,550 email addresses on record with the American College of Veterinary Pharmacists, the International Academy of Compounding Pharmacists, and the Society of Veterinary Hospital Pharmacists. The survey asked questions about regulations and standards associated with the use of prescription or compounded medications. Of the 4,550 distributed surveys, 153 were received, for a 3.4% response rate. Of the responses received, only 131 were used in the final data analysis. Most respondents correctly answered the assessment question regarding the ability to compound backordered, commercially available products. A majority of respondents incorrectly answered the question regarding the proper flavoring for a medication for a ferret. Those with more training perceived themselves to have a higher level of skill (r = 0.41, P<0.001). Similarly, those with formal veterinary training had better scores on Question 4 of the assessment questions, which requires knowledge of feline toxicities (P=0.029). The most common compounded medications dispensed in practice by pharmacists are methimazole, metronidazole, and gabapentin. Pharmacists mostly recognized that compounding backordered, commercially available products is permitted. Formal training improves familiarity with current compounding rules, regulations, and best practices. Formal training in veterinary pharmacy and veterinary compounding should be promoted and encouraged. Efforts should also be made at improving pharmacists' understanding of both veterinary and compounding laws and regulations.

Ketamine Tolerance in Sprague-Dawley Rats after Chronic Administration of Ketamine, Morphine, or Cocaine.

Ketamine is one of the most commonly used anesthetics in human and veterinary medicine, but its clinical effectiveness is often compromised due to tolerance to its anesthetic effects. Although ketamine tolerance has been demonstrated in a number of behavioral measures, no published work has investigated tolerance to ketamine's anesthetic effects other than duration of anesthesia. In addition, a reported practice in anesthesiology is to alter anesthetic doses for procedures when the patient has a history of drug abuse. Empirically investigating the effects of administration of a drug of abuse on ketamine's potency and efficacy to produce anesthesia could help in the creation of anesthetic plans that maximize safety for both clinicians and patients. The goal of the current study was to test the effects of repeated administration of ketamine, morphine, or cocaine on ketamine's ability to produce anesthesia. In 2 studies, male Sprague-Dawley rats received daily injections of ketamine (32 or 100 mg/kg IP), morphine (3.2 or 5.6 mg/kg IP), or cocaine (3.2 or 10 mg/kg IP) for 14 consecutive days and then were tested on day 15 for ketamine-induced anesthesia by using a cumulative-dosing procedure (32 to 320 mg/kg IP). Chronic treatment with either ketamine or morphine-but not cocaine-produced tolerance to ketamine's anesthetic effects in a dose-dependent manner. These results suggest that ketamine's clinical effectiveness as an anesthetic will vary as a function of its history of use. Furthermore, given that chronic morphine administration produced tolerance to ketamine's anesthetic effects, various pain medications may reduce ketamine's effectiveness for anesthesia.

Compounding from a Pharmacy Student's Perspective.

The International Academy of Compounding Pharmacists' Foundation held a student essay contest in the Spring of 2018. Two great submissions were chosen to receive an award. This article features one of the chosen essays, which discusses the benefits that compounding pharmacies/pharmacists offer patients and discusses the importance and advantages of owning/operating a compounding pharmacy.