Aplastic Anemia From Veterinary Phenylbutazone

Ramsey, Robert H.

doi:10.1001/jama.1976.03270100049030

Cited by 10 publications

(5 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Given the genuine risks to human health from misdirection, the panel has concerns about the open supply of this medicine, given that sales of nonprescription medications are controlled to reduce the chance of deliberate overdose. BEVA produce a client information leaflet that sets out these safety concerns and recognises that deliberate self‐administration of many oral equine medications would have long‐term effects on individuals . The oral bioavailability of paracetamol has been documented following a dose rate of 10 mg/kg bwt and has been described in a single case when administered at 20 mg/kg .…”

Section: Resultsmentioning

confidence: 99%

BEVA primary care clinical guidelines: Analgesia

Bowen

Redpath

Dugdale

et al. 2019

Equine Veterinary Journal

View full text Add to dashboard Cite

Summary Primary care guidelines provide a reference point to guide clinicians based on a systematic review of the literature, contextualised by expert clinical opinion. These guidelines develop a modification of the GRADE framework for assessment of research evidence (vetGRADE) and applied this to a range of clinical scenarios regarding use of analgesic agents. Key guidelines produced by the panel included recommendations that horses undergoing routine castration should receive intratesticular local anaesthesia irrespective of methods adopted and that horses should receive NSAIDs prior to surgery (overall certainty levels high). Butorphanol and buprenorphine should not be considered appropriate as sole analgesic for such procedures (high certainty). The panel recommend the continuation of analgesia for 3 days following castration (moderate certainty) and conclude that phenylbutazone provided superior analgesia to meloxicam and firocoxib for hoof pain/laminitis (moderate certainty), but that enhanced efficacy has not been demonstrated for joint pain. In horses with colic, flunixin and firocoxib are considered to provide more effective analgesia than meloxicam or phenylbutazone (moderate certainty). Given the risk of adverse events of all classes of analgesic, these agents should be used only under the control of a veterinary surgeon who has fully evaluated a horse and developed a therapeutic, analgesic plan that includes ongoing monitoring for such adverse events such as the development of right dorsal colitis with all classes of NSAID and spontaneous locomotor activity and potentially ileus with opiates. Finally, the panel call for the development of a single properly validated composite pain score for horses to allow accurate comparisons between medications in a robust manner.

show abstract

Section: Resultsmentioning

confidence: 99%

BEVA primary care clinical guidelines: Analgesia

Bowen

Redpath

Dugdale

et al. 2019

Equine Veterinary Journal

View full text Add to dashboard Cite

show abstract

“…As well as a number of individual case histories (Hale and De Gruchy, 1960;Lander and Bonnin, 1962;McCarthy and Chalmers, 1964;Cameron et al, 1966), Ramsey and Golde (1976) summarised 10 earlier reports in which marrow depression was associated with use of phenylbutazone. These authors further reported that, in any given week in 1962, 100,000 humans in Great Britain were receiving phenylbutazone therapy.…”

Section: Blood Dyscrasias: Clinical Datamentioning

confidence: 99%

“…There is some evidence to indicate that dyscrasias are dose related. Ramsey and Golde (1976) noted that, 'although the mechanism of phenylbutazone-induced hematologic toxicity is not known, there is some evidence that it is dose related. The incidence of leukopenia, thrombocytopenia, anaemia, and aplastic anaemia in the earliest clinical trials using up to 1.6 g daily was considerably higher than later trials using lower dosages'.…”

Section: Blood Dyscrasias: Mechanisms Of Myelotoxicity and Concentratmentioning

confidence: 99%

Pharmacokinetics, pharmacodynamics, metabolism, toxicology and residues of phenylbutazone in humans and horses

Lees

Toutain

2013

The Veterinary Journal

View full text Add to dashboard Cite

The presence of horse meat in food products destined for human consumption and labelled as beef has raised several concerns of public interest. This review deals solely with one aspect of these concerns; samples of equine tissue from horses destined for the human food chain have tested positive for the non-steroidal anti-inflammatory drug, phenylbutazone. The safety of some or all such foods for human consumers is a major concern, because it was shown many years ago that phenylbutazone therapy in humans can be associated with life threatening blood dyscrasias. As an initial basis for assessing the potential toxicity of foods containing phenylbutazone and its metabolites, this article reviews (1) the pharmacokinetic, pharmacodynamic, metabolic and toxicological profiles of phenylbutazone, with particular reference to horses and humans; (2) toxicity data in laboratory animals; (3) phenylbutazone residues in food producing species, and (4) as a preliminary assessment, the potential hazard associated with the consumption of horse meat containing phenylbutazone and its metabolites. Since phenylbutazone cannot be classified as a carcinogenic substance in humans, and noting that blood dyscrasias in humans are likely to be dose and treatment duration-dependent, the illegal and erratic presence of trace amount residues of phenylbutazone in horse meat is not a public health issue.

show abstract

“…There are other examples of veterinary phenylbutazone that induced side effects in humans including blood dyscrasias. 42,43 Children are especially sensitive to phenylbutazoneinduced bone marrow suppression. 44 Adding to the complexity of the phenylbutazone-induced blood dyscrasias is the half-life in humans versus horses.…”

Section: Discussionmentioning

confidence: 99%

A review of horses sent to slaughter for human consumption: impact of horsemeat consumption, residual banned drugs, and public health risks

Weber¹,

Kearley²,

Marini

et al. 2023

ajvr

View full text Add to dashboard Cite

Nearly all of the American horses exported to Mexico and Canada are slaughtered for human consumption, and their meat is either exported around the world or consumed locally. Previous work showed that 18 Thoroughbred racehorses purchased by rescues that would have otherwise been sold for export for the sole purpose of slaughter to produce meat for human consumption were administered phenylbutazone. We report the number of American horses exported to Canada and Mexico from 2016 to 2021, the presence of contaminated horsemeat from Canadian slaughterhouses, and the human use and idiosyncratic effects of veterinary phenylbutazone and side effects of clenbuterol, 2 of the drugs that were found in contaminated Canadian horsemeat. The number of live American horses exported to Canada declined precipitously from 2016 to 2017, and a second decline occurred in 2020. All food-producing animals are under strict regulatory control to prevent animals administered banned drugs to enter the food chain. A major principle of this program is zero tolerance for banned drugs and testing for compliance. No regulatory process is in place to remove horses administered banned drugs such as phenylbutazone. The efficacy lasts for more than 24 hours as a result of the irreversible binding to cyclooxygenase, slow elimination, and long elimination half-life of its metabolite oxyphenbutazone. High or frequent doses of phenylbutazone result in disproportionately increased plasma concentrations, which result in the residual presence in tissues. It is this fact that underlies the ban of this drug in food-producing animals. No human clinical surveillance program is in place to monitor individuals on the possible short- and long-term consequences of banned drugs in contaminated horsemeat. If the United States is unable to put in place a regulatory program to remove horses administered banned drugs as exists for all food-producing animals, the exportation of American horses across both borders for the sole purpose of slaughter for human consumption must end.

show abstract

Aplastic Anemia From Veterinary Phenylbutazone

Cited by 10 publications

References 3 publications

BEVA primary care clinical guidelines: Analgesia

BEVA primary care clinical guidelines: Analgesia

Pharmacokinetics, pharmacodynamics, metabolism, toxicology and residues of phenylbutazone in humans and horses

A review of horses sent to slaughter for human consumption: impact of horsemeat consumption, residual banned drugs, and public health risks

Contact Info

Product

Resources

About