Review of the Mechanism of Action and Use of Bisphosphonates in Horses.
Authors: Yocom Alicia, Contino Erin, Kawcak Christopher
Journal: Journal of equine veterinary science
Summary
# Editorial Summary: Bisphosphonates in Equine Practice Bisphosphonates represent a distinct class of anti-resorptive agents with particular relevance to managing bone pathology in horses, functioning primarily by binding to hydroxyapatite crystals within exposed bone matrix where they are subsequently internalised by osteoclasts, thereby suppressing their resorptive activity. Beyond this direct mechanism, these drugs exert secondary effects including pain modulation, inflammatory reduction, and alterations to macrophage behaviour that may enhance their therapeutic utility. The 2023 review by Yocom and colleagues synthesises current knowledge of bisphosphonate pharmacology specific to equine medicine, distinguishing between nitrogenous and non-nitrogenous compounds and examining why the latter classification predominates in equine clinical application, whilst contextualising these effects within the broader framework of pathological bone remodelling. Critical evaluation of safety data, efficacy evidence, and regulatory considerations provides practitioners with the evidence base necessary to make informed decisions regarding bisphosphonate use in conditions ranging from bone spavin and navicular disease to fracture management and osteoarthritis. For farriers, veterinarians, and allied equine professionals, understanding these mechanisms and their evidence base is essential for appropriate case selection and realistic discussion of therapeutic timelines with clients.
Read the full abstract on PubMed
Practical Takeaways
- •Bisphosphonates offer a multi-target approach to bone disease management in horses beyond simple anti-resorptive effects, including pain and inflammation reduction
- •Understanding the distinction between nitrogenous and non-nitrogenous bisphosphonates is critical, as only non-nitrogenous forms are approved for equine use
- •Practitioners should review current safety data and regulatory guidelines before implementing bisphosphonate therapy in clinical practice
Key Findings
- •Bisphosphonates reduce bone resorption by incorporating into hydroxyapatite crystal structure and being taken up by osteoclasts
- •Non-nitrogenous bisphosphonates are the type used in equine medicine, while nitrogenous types are used in human medicine
- •Bisphosphonates have multiple mechanisms of action including pain reduction, inflammation reduction, and alteration of macrophage function
- •Literature review includes safety data and current regulatory rules for bisphosphonate use in horses