Pharmacotherapeutic group: Bisphosphonate, Clodronic acid.
ATCvet code: QM05BA02
Pharmacodynamic properties
Clodronic acid is a geminal bisphosphonate that inhibits bone resorption by binding to hydroxyapatite crystals (inhibiting their formation and dissolution), and by direct cellular effects on osteoclasts (inhibiting osteoclast cell function). It has a high affinity for solid-phase calcium phosphate and therefore accumulates in bone, where it inhibits the formation, aggregation and dissolution of calcium phosphate crystals. Bound to bone matrix, clodronic acid enters resorbing osteoclasts, alters their morphology and reduces the number of active osteoclasts, regardless of the cause of osteoclast activity. Clodronic acid increases bone mass by inhibiting bone resorption and retarding bone turnover.
Pharmacokinetic properties
The pharmacokinetic profile after a single intramuscular administration of 765 mg clodronic acid in horses diagnosed with navicular syndrome is characterised by rapid absorption of clodronic acid and a longer terminal elimination phase. The plasma half-life is approximately 11.8 hours + 12.5 hours (mean + standard deviation), Cmax is 7.5 + 1.7 μg/ml and time to maximum concentration (Tmax) is approximately 0.6 hours.