Comparative evaluation of isosorbide mononitrate and alendronate in management of postmenopausal osteoporosis

Osteoporosis, a skeletal disorder that adversely affects bone strength , is common among postmenopausal women primarily due to reduced ovarian estrogens.

The present study was taken up to evaluate the role of isosorbide mononitrate (IMN) in the management of postmenopausal osteoporosis and to compare its efficacy with that of alendronate.

This prospective systematic randomized study was conducted on 90 postmenopausal women with lumbar spine BMD >2.5 SD below the young adult reference range. The participants received either Tab Alendronate 70 mg orally, once weekly (Group I) or Tab IMN 40 mg orally once daily (Group II) for 9 months, in addition to 500 mg of oral calcium daily. The BMD of the lumbar spine was measured using DEXA scan at enrolment and after 9 months. The data was analyzed by Student's t test and Chi-square test.

The mean baseline BMD was 0.67 + 0.097 and 0.68 + 0.067 g/cm(2) in Group I and II, respectively. An increase of 11.94% in the mean BMD was noted after 9 months of treatment with alendronate as against 8.82% with IMN. Headache, flushing and palpitations in Group II and nausea, epigastric pain and heart burn in Group I were the most common adverse effects.

IMN has a beneficial effect on bone turnover in cases of postmenopausal osteoporosis and that the effect is comparable to that of alendronate. IMN is a promising and safe alternative to alendronate for the management of postmenopausal osteoporosis.