A once weekly formulation of alendronate sodium (Fosamax) has been developed. According to Merck Sharp & Dohme, the UK manufacturer, it is therapeutically equivalent to the standard daily treatment for treating postmenopausal osteoporosis.
The new formulation could improve compliance with alendronate therapy, which at present is given daily with instructions to take the drug with water on an empty stomach at least 30 minutes before breakfast, and then to sit or stand upright for at least 30 minutes.
Details of a study comparing the weekly and daily dosages were announced this week at an international symposium on bone and mineral metabolism, in Venice. The study included 1,258 postmenopausal women with osteoporosis. Alendronate was given in dosages of 70mg weekly, 35mg twice weekly or 10mg daily. All women received calcium and vitamin D supplements. At the end of one year, increases in bone mineral density and markers of bone turnover were similar in the different treatment groups.
MSD says that the data from the study will be submitted to regulatory agencies with a view to getting a licence for the weekly dosage. The company describes Fosamax as the only widely used medication for a common condition which has been shown to be effective when taken only once weekly.