Modification of empirical antimicrobial regimens in large animal medicine

BACKGROUND

Empirical antimicrobial regimens can be modified following new diagnostic information or when empirical treatment fails. Little is known about the frequency or clinical context in which these modifications occur. We characterised these modifications in a large animal hospital to identify when antimicrobial use could be optimised.

METHODS

Chart reviews were performed for all inpatients and outpatients administered antimicrobials at a large animal veterinary referral and teaching hospital in 2017-2018 (n=1163 visits) to determine when and why empirical regimens were modified. Multinomial logistic regression was performed to identify factors associated with reasons for modification.

RESULTS

Empirical antimicrobial regimens were modified in 17.3 per cent of visits. The main reasons were parenteral-oral conversions in horses and failure of disease prevention or treatment in ruminants. Empirical therapy for disease prevention was more likely to be modified because of complications in ruminants and in animals on the emergency/critical care service. Empirical therapy for disease treatment was more often modified for reasons other than de-escalation in ruminants and in animals with longer lengths of stay.

CONCLUSIONS

Empirical antimicrobial regimens were modified infrequently and mostly for purposes of parenteral-oral conversion in horses and lack of response in ruminants. De-escalation of antimicrobials administered for disease treatment, when guided by diagnostics, is a major tenet of judicious antimicrobial use. However, more research is needed to determine when and how antimicrobial regimens administered for disease prevention should be modified.

To prescribe or not to prescribe? A factorial survey to explore veterinarians' decision making when prescribing antimicrobials to sheep and beef farmers in the UK

Resistance to antimicrobials is one of the biggest challenges worldwide for public health. A key strategy for tackling this is ensuring judicious use of antimicrobials in human and veterinary medicine. Whilst there are many studies in human medicine investigating prescribing behaviour of doctors, there is limited work to understand what factors influence veterinarian prescribing behaviour. Veterinarians often prescribe antimicrobials to sheep and beef farmers in contexts other than at a clinical consultation, and decision-making behind this has not been explored. The aim of this study was to measure, for the first time, the influence of factors from social theories on veterinarians' decision to prescribe antimicrobials to sheep and beef farmers without a clinical consultation, using a factorial survey approach. Respondents were presented with eight vignette scenarios, where a farmer asks for antimicrobials at the veterinary practice. Seven factors, identified from constructs of social theories, were included in the vignettes. Random intercept and random slope models were built to estimate the effects of the vignette factors and vet characteristics on the respondents' willingness to prescribe ratings. A total of 306 surveys were completed. The vignette factors: case type, farmer relationship, other veterinarians in practice, time pressure, habit, willingness to pay, and confidence in the farmer, were significant in the decision to prescribe. Confidence in the farmer was the most influential vignette variable, and was included as a random slope effect. Respondent variables with significant influence on the decision to prescribe were agreeableness personality score, region of veterinary practice, and presence of a small animal department. These influential factors could be considered to target interventions in beef and sheep farm animal veterinary practice for improved antimicrobial stewardship.

[Medicinal products for human use in veterinary prescription]

The paper deals with the problem of prescription and use of the medicinal products for human use in veterinary medicine. Using partial model analysis describes volume and structure of the prescription of medicinal products for human use in the veterinary practice in the years 2007-2011. Prescriptions included to the study were dispensed in a community pharmacy located in a county town in the Slovak Republic. Data were obtained from the basic collection of 845 veterinary prescriptions that included 1178 prescribed items in a total of 2954 packages.

Antimicrobial dispensing by Ontario dairy veterinarians

This questionnaire-based cross-sectional study was designed to capture the demographics of dairy practitioners in Ontario and to describe aspects of antimicrobial dispensing on-farm and over-the-counter by these veterinarians. The information collected revealed that the prescription status of a drug and the level of veterinary-client-patient relationship were important elements of dispensing policies. Over-the-counter dispensing records were incomplete, while only a small proportion of on-farm dispensing records contained pertinent information and directions as required by the Veterinarians Act. While respondents recognized that antimicrobial use in dairy herds could lead to resistance in cattle, few indicated that this was a significant public health issue. Veterinarians can play a key role in antimicrobial stewardship, part of which is the provision of complete written dispensing instructions to producers for antimicrobial use in dairy cattle.

Outcomes from homeopathic prescribing in veterinary practice: a prospective, research-targeted, pilot study

BACKGROUND AND AIMS

Targeted research development in veterinary homeopathy is properly informed by the systematic collection and analysis of relevant clinical data obtained by its practitioners. We organised a pilot data collection study, in which 8 Faculty of Homeopathy veterinarians collected practice-based clinical and outcomes data over a 6-month period.

METHODS

A specifically designed Excel spreadsheet enabled recording of consecutive clinical appointments under the following headings: date; identity of patient and owner (anonymised); age, sex and species of patient; medical condition/complaint treated; whether confirmed diagnosis, chronic or acute, new or follow-up case; owner-assessed outcome (7-point Likert scale: -3 to +3) compared with first appointment; homeopathic medicine/s prescribed; other medication/s for the condition/complaint. Spreadsheets were submitted monthly by e-mail to the project organisers for data checking, synthesis and analysis.

RESULTS

Practitioners submitted data regularly and punctually, and most data cells were completed. 767 individual patients were treated (547 dogs, 155 cats, 50 horses, 5 rabbits, 4 guinea-pigs, 2 birds, 2 goats, 1 cow, and 1 tortoise). Outcome from two or more homeopathic appointments per patient condition was obtained in 539 cases (79.8% showing improvement, 6.1% deterioration, 11.7% no change; outcome not recorded in 2.4% of follow-ups). Strongly positive outcomes (scores of +2 or +3) were achieved in: arthritis and epilepsy in dogs and, in smaller numbers, in atopic dermatitis, gingivitis and hyperthyroidism in cats.

CONCLUSIONS

Systematic recording of data by veterinarians in clinical practice is feasible and capable of informing future research in veterinary homeopathy. A refined version of the spreadsheet can be used in larger-scale research-targeted veterinary data collection.

Antimicrobial agents are societal drugs: how should this influence prescribing?

This paper is concerned with how those who prescribe antimicrobials should consider the wider repercussions of their actions. It is accepted that in an ecological system, pressure will cause evolution; this is also the case with antimicrobials, the result being the development of resistance and the therapeutic failure of drugs. To an extent, this can be ameliorated through advances by the pharmaceutical industry, but that should not stop us from critically appraising our use and modifying our behavior to slow this process down.

Up to 50% of prescribing in human medicine and 80% in veterinary medicine and farming has been considered questionable. The Alliance for the Prudent Use of Antimicrobials (APUA) was approached by the WHO to review the situation. Their recommendations include decreasing the prescribing of antibacterials for nonbacterial infections. In the UK, there has been an initiative called ‘the path of least resistance’. This encourages general practitioners to avoid prescribing or reduce the duration of prescriptions for conditions such as upper respiratory tract infections and uncomplicated urinary tract infections; this approach has been successful. Another recommendation is to reduce the prescribing of broad-spectrum antibacterials. In UK hospitals, the problems identified with the inappropriate use of antibacterials are insufficient training in infectious disease, difficulty in selecting empirical antibacterial therapy, poor use of available microbiological information, the fear of litigation and the fact that the majority of antibacterials are prescribed by the least experienced doctors. With close liaison between the laboratories and clinicians, and the development of local protocols, this can be addressed. Another recommendation is to tighten the use of antibacterial prophylaxis and to improve patient compliance. Through a combination of improved education for doctors and patients, and improved communication skills, these problems can be addressed. A further recommendation is to encourage teaching methods that modify prescribing habits. It has been shown that workshops have led to a significant reduction in the prescribing of broad-spectrum antibacterials in the community. Auditing the prescribing of antibacterials has also been recommended.

Surveillance systems around the world monitor trends in resistance: the European Antimicrobial Resistance Surveillance Progamme (EARSS) monitors antibacterial resistance; the WHO and the International Union Against Tuberculosis and Lung Disease collaborate to monitor tuberculosis; the WHO and the International AIDS Society monitor HIV.

In the third world, a bigger problem than resistance is whether drugs are even effective, as they are often spoiled by climactic conditions, and poor quality generics and counterfeit drugs are common. Also, patients may not be able to complete a course for financial reasons.

Facts about Antimicrobial resistance in Animals (and agriculture) and Impact on Resistance (FAAIR) was commissioned by APUA. They conclude that the nonhuman use of antibacterials can lead to the development of antibacterial resistance in human pathogens. The European commission banned the use of antibacterials as growth promoters in 1999.

In the Western world, we should improve our diagnosis of sepsis, access local guidelines and consider withholding treatment pending investigations, decide if treatment can be stopped earlier and treat the patient not the result. Many developing countries need improved access to more antimicrobials, preferably in the controlled environment of appropriate medical advice.

Investigation of antimicrobial use and the impact of antimicrobial use guidelines in a small animal veterinary teaching hospital: 1995-2004

OBJECTIVE

To evaluate patterns of antimicrobial use and the impact of antimicrobial use guidelines at a small animal veterinary teaching hospital.

DESIGN

Retrospective study.

SAMPLE POPULATION

All antimicrobial prescriptions for dogs and cats admitted to the hospital in 1995 through 2004.

PROCEDURE

Pharmacy records were reviewed, and antimicrobial prescriptions for all dogs and cats admitted during the study period were recorded. Amounts of individual drugs dispensed directly to the intensive care and surgical units were determined. Changes in antimicrobial use during the study period were assessed; changes in antimicrobial use patterns in 2000 through 2004 were evaluated to assess the impact of implementation of antimicrobial use guidelines in 2001.

RESULTS

There was a significant decrease in prescriptions/1,000 admissions during the study period. From 1995 to 2004, the use of first-generation cephalosporins, fluoroquinolones, penicillins, and trimethoprim-sulfonamides decreased, whereas the use of metronidazole increased. The use of first-generation cephalosporins, fluoroquinolones, and penicillins decreased from 2000 to 2004. First-line drugs accounted for 90.7% of prescriptions during the study period. The use of third-line drugs decreased from 2000 to 2004.

CONCLUSIONS AND CLINICAL RELEVANCE

Characterization of antimicrobial use is an important step in defining and evaluating the prudent use of antimicrobials. Whereas the true effect of antimicrobial use guidelines is unclear, these results suggest that the guidelines may have had an effect on antimicrobial prescription patterns in this small animal veterinary teaching hospital. Analysis of objective data regarding antimicrobial use and changes in antimicrobial use patterns over time is important in veterinary practices.

Prescription-only anthelmintics--a questionnaire survey of strategies for surveillance and control of equine strongyles in Denmark

In 1999, legislation in Denmark made anthelmintic drugs available only by prescription, and prohibited their use for routine, prophylactic treatment. A questionnaire survey was conducted in 2004 to determine current strategies for surveillance and control of equine strongyles used in Danish equine veterinary practices. Eighty-seven of 170 (51.2%) registered equine veterinary practices responded. Ninety seven percent of the respondents used faecal egg counts for diagnosis and surveillance, and 41% used larval cultures. Logistic regression revealed that the use of larval cultures was positively correlated with numbers of employees (P = 0.013) and the proportion of equine caseload in the practice (P < 0.000). Performing faecal egg counts and treating horses was most frequent during spring, summer and early autumn. Veterinary practices made treatment decisions based on cut-off values ranging from 20 to 500 eggs per gram (EPG) faeces. Ages of horses, clinical suspicions of parasitic disease, or requests by the owners were the most important factors in the strategies for faecal sampling. Less commonly, sampling strategies included all horses on the premises and random sampling. Ninety five percent of the respondents reported treating certain groups of horses without prior faecal analysis, including horses with clinical signs of parasitic disease (77%), foals (84%), horses less than 3 years of age (52%), and pregnant mares (51%). The respondents regarded the cyathostomin group as the most prevalent cause of parasitic disease and ill-thrift, followed by large strongyles and Parascaris equorum. Sixty seven percent rotated regularly between drugs, while 11% performed routine screening for anthelmintic resistance. Results of this survey suggest that limiting equine anthelmintics to prescription-only availability has increased the level of strongyle surveillance. Veterinary practitioners play a central role in equine parasite management with indications of a lowered intensity of treatment. However, screening for anthelmintic resistance remains uncommon.

Survey of condition-based prescribing of antimicrobial drugs for dogs at a veterinary teaching hospital

A database of the prescriptions of antimicrobial drugs for the treatment of common infectious diseases in dogs at the Finnish Veterinary Teaching Hospital was searched to determine to what extent national guidelines were being followed. Twenty-two per cent of 5918 dogs were treated orally with antimicrobial drugs. The most commonly used drugs were beta-lactams (49 per cent) of which cephalexin and amoxycillin-clavulanate were most widely prescribed. The usage of fluoroquinolones was only 2.8 per cent. The prescription of antimicrobials for pyoderma was contrary to Finnish guidelines, but the use of cephalexin or amoxycillin-clavulanate as first-line drugs instead of macrolides or lincosamides or trimethoprim-sulphonamides was acceptable because of the presence of resistance by canine staphylococci. The drug most commonly used to treat acute urinary tract infections was trimethoprim-sulphonamide, in agreement with the guidelines. Antimicrobial drugs were used excessively after surgical procedures, and for treating acute gastrointestinal disturbances and small wounds and traumas.

Regulation of veterinary antibiotics in Australia

The Australian Pesticides and Veterinary Medicines Authority (APVMA)* registers veterinary antibiotic products before they can be supplied, distributed or sold in Australia. Extensive scientific assessment on all new veterinary antibiotic products is undertaken for the APVMA by experts in other government agencies including the Therapeutic Goods Administration (toxicology), the National Occupational Health and Safety Commission (occupational health and safety), Environment Australia (environmental hazards) and state departments of agriculture or primary industry (efficacy and safety) as well as APVMA assessments on food residues, trade and manufacturing. The National Health and Medical Research Council Expert Advisory Group on Antimicrobial Resistance provides advice to the APVMA on the potential transfer of antibiotic resistance from the use of antibiotics in animals to humans, and the impact transfer may have on public health. Food Standards Australia New Zealand (previously Australia New Zealand Food Authority) set maximum residue levels for human foods. The APVMA monitors registered product use through compliance activities and an adverse experience reporting program, and reviews registered products as necessary. The import, manufacture, supply and use of veterinary antibiotics are regulated by Commonwealth and State governments in Australia.