Osphos (clodronate injection) contains clodronate disodium and is administered intramuscularly.

Clodronate disodium inhibits bone resorption by reducing the number of active osteoclasts regardless of the cause of osteoclast activity and inhibits of the formation and dissolution of calcium phosphate crystals in the bone matrix.

The main effect of a bisphosphonate is to decrease bone resorption.

Bisphosphonates act to inhibit bone resorption by decreasing the number and activity of osteoclasts by inducing apoptosis, or cell death. During bone stress or disease, bone metabolism is accelerated and osteoclasts are stimulated to begin the remodeling cycle. Osteoblasts follow behind the bone-eating cells, but at a much slower pace.

Accelerated bone resorption may exceed the bone rebuilding process during these times of chronic bone disease or stress, including navicular syndrome. ¹

1. Fleisch, Hi. Biological effects. Bisphosphonates in bone disease; from the laboratory to the patient (2.3.2), 34-51, 2000. San Diego, Academic Press