Tiludronate Disodium
Tiludronic Acid
Also known as: Tildren · Skelid · Tiludronic acid · ME-3737 · SR-41319 · acidum tiludronicum
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Dosing by species
🌎 NA — North America🌍 EU — Europe
Horses
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Navicular disease | 0.1 mg/kg tiludronic acid slow IV (over 20-30 seconds per 10 mL given) | IV | once daily | 10 days | 🌎 NA |
- Navicular disease: Alternate injection sites from day to day.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Tiludronate disodium (also known as tiludronic acid) is a non-nitrogenous bisphosphonate medication primarily utilized in equine medicine to inhibit bone resorption.
It is most notably indicated for the intravenous treatment of navicular disease and distal tarsal osteoarthritis (bone spavin) in horses. By regulating bone remodeling and decreasing localized inflammation, it can significantly improve lameness associated with these conditions, particularly when administered early in the disease process.
Clinical Pearl: As a non-nitrogenous bisphosphonate, tiludronate is generally considered less potent than newer nitrogen-containing bisphosphonates (like zoledronate), but it has a well-established safety and efficacy profile for equine osteoarticular conditions. In human medicine, an oral formulation is used to treat Paget's disease.
Mechanism of action
Tiludronate works by inhibiting osteoclastic bone resorption.
- Binding: The drug has a high affinity for calcium and binds strongly to hydroxyapatite crystals in the bone matrix, preferentially at sites of active bone turnover (cancellous bone > cortical bone).
- Cellular Uptake: During bone resorption, osteoclasts take up the bisphosphonate.
- Intracellular Mechanism: As a non-nitrogenous bisphosphonate, tiludronate is intracellularly metabolized into a non-hydrolyzable ATP analogue.
- Apoptosis: This toxic ATP analogue accumulates within the osteoclast → disrupts cellular energy metabolism (inhibiting ATP-dependent intracellular enzymes) → induces osteoclast apoptosis (programmed cell death).
- Result: Decreased osteoclast function and lifespan lead to a net reduction in bone resorption and stabilization of bone remodeling.
Safety & warnings
Contraindications
- Renal dysfunction
- Horses producing milk for human consumption
- Horses less than 3 years old (due to lack of data on growing skeletons)
- Pregnant or lactating mares
Adverse effects
- Colic (reduced appetite, abdominal discomfort, pawing, restlessness)
- Muscle tremor (associated with hypocalcemia)
- Fatigue/lassitude
- Sweating
- Injection site reactions (e.g., phlebitis, especially after repeated injections)
- Salivation
- Tail hypertonia
Precautions
Important Warnings:
- Hypocalcemia Risk: Use with extreme caution in horses with pre-existing hypocalcemia or cardiac dysfunction. Bisphosphonates can acutely lower serum calcium levels.
- Administration Rate: If used in high-risk patients, slow the rate of injection significantly and monitor closely for the first few hours post-injection.
- Age Restrictions: Avoid use in young, growing animals (< 3 years old) as the effects on skeletal development are not fully established.
- Renal Clearance: The drug is eliminated unchanged by the kidneys; avoid in patients with renal impairment.
Drug interactions
May complex with tiludronate and reduce its availability; do not mix or administer concurrently.
Monitoring
- Clinical Efficacy (improvement in lameness)
- Serum Calcium levels
- Adverse Effects (particularly within the first 4 hours after dosing, watching for colic or muscle tremors)
Pharmacokinetics
Half-life
Absorption
Rapidly distributed to bone after intravenous injection.
Distribution
Binds strongly to bone hydroxyapatite, with greater binding to cancellous bone than cortical bone. Plasma protein binding is approximately 85%.
Metabolism
Not extensively metabolized; acts directly on osteoclasts.
Elimination
Unbound drug is eliminated unchanged in the urine. Approximately 25-50% of a single IV dose is eliminated in the urine over 96 hours. Repeated daily doses do not result in plasma accumulation.
Overdose
Limited information is available regarding massive overdose.
- Clinical Signs: The manufacturer reports that doses of 3X the therapeutic dose in horses caused an increased frequency of adverse effects, particularly signs of colic and muscle tremor.
- Treatment: Intravenous calcium administration should be considered for signs associated with acute hypocalcemia (e.g., severe muscle fasciculations/tremors). Conventional colic treatments are recommended if gastrointestinal signs persist.
Available products
Formulations
- Injection (veterinary)
- Oral tablets (human)
Veterinary
- Tiludronic Acid: 50 mg (as tiludronate disodium) per vial, with one 10 mL vial of sterile water for reconstitution; Tildren (Sanofi/Ceva)
Human-labeled
- Tiludronate Disodium Oral Tablets: 240 mg (equiv. to 200 mg tiludronic acid); Skelid (Sanofi-Aventis)
Regulatory status
No regulatory data for: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Store the unreconstituted powder and diluent at room temperature (15-30°C) in the outer carton. Shelf life of properly stored unreconstituted product is generally 3 years. Reconstitute the powder by aseptically adding 10 mL of the provided diluent and mix gently (resulting in 5 mg/mL). After reconstitution, use immediately and discard any remaining product. Do not mix or administer with intravenous fluids containing calcium or magnesium.
Client information
Important Information for Horse Owners
- Professional Administration: This medication must be administered intravenously by a licensed veterinary professional.
- Post-Treatment Observation: Your horse should be closely observed for up to 4 hours after the injection.
- What to Watch For: Contact your veterinarian immediately if you notice signs of colic (pawing, looking at the flank, restlessness, loss of appetite) or muscle tremors/twitching (which can indicate a temporary drop in blood calcium).
- Rest and Recovery: Follow your veterinarian's specific instructions regarding exercise and rest during the treatment period for navicular disease.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.