Effective Dosage and Administration Schedule of Oral Alendronate for Non-nociceptive Symptoms in Rats with Chronic Constriction Injury

We evaluated the efficacy of oral alendronate with different dosing regimens for non-nociceptive symptoms and osteoporosis in a sciatic nerve chronic constriction injury (CCI) model. Male Sprague-Dawley rats (n=60) were subdivided into sham control (SC) group and CCI groups, which were divided according to dosage and time of oral alendronate administration: no treatment (NT), low dosage early (LE), high dosage early (HE), low dosage late (LL) and high dosage late (HL). We measured the thickness and temperature of the hind paw, bone mineral density (BMD) of the tibia, along with tibia bone strength. On the 14th day post-CCI, the HE group showed significant reduction in thickness and temperature (P<0.001). On the 42nd day post-CCI, the HE group showed significant reduction in temperature compared to the NT group (P<0.001). Also, both HE and HL groups showed statistically significant increased tibia BMD (P<0.001), along with increase of tibia bone strength compared to the NT group. Based on these findings, early alendronate in high dosages is effective in the non-nociceptive symptoms; early and late alendronate in high dosages, are effective in preventing bone dystrophic changes in a CCI model.