Intermittent or Continuous Treatment with Monofluorophosphate alone in the combination with Antiresorptive

Intermittent or Continuous Treatment with Monofluorophosphate alone in the combination with Antiresorptive: Current data and perspectives.

J.D. Ringe Dept. Of Internal Medicine 4, Klinikum Leverkusen,      University of Cologne, Germany

Paper republished with permission of its authors

The optimal formulation and regimen of fluoride for osteoporosis are still a matter of discussion. Doses around 20 mg/day given as continuous monofluorophosphate (MFP) or long-cycle slow-release NaF, plus calcium supplementation for up to 4 years, decrease vertebral fracture rate especially in moderate osteoporosis, while the effects in more severe stages is unclear, especially for shorter treatments.

We hypothesised that even lower doses given in an intermittent fashion (15 mg/day fluoride given as MFP, 3 months-on/1 month-off) could show optimal effects in different patients. In a first, 3-year randomised study in 64 men with primary osteoporosis (L2-L4 T score<-2.5) and no previous vertebral fractures, this regimen significantly decreased the incidence of vertebral fractures when compared to calcium only, with BMD increasing at both trabecular and cortical sites and a trend for reduction also in non-vertebral fractures.

In a second randomised study in 134 postmenopausal patients with severe, established osteoporosis (3.6 vertebral fractures/patient in average), both this intermittent and a continuous MFP regimen (20 mg fluoride + 1000 mg calcium) exhibited significantly (p<0.001) lower vertebral fracture rates than calcium alone after 3 years. A non-significant better trend was observed for the former (8.6 vs. 19.0 vs. 31.6 new fractures/100 pt-yrs, respectively), despite a lower increase in spinal BMD but with a better preservation of cortical bone. A similar pattern was evident for non-vertebral fractures, that also significantly decreased in both MFP groups. Adverse effects (e.g. lower limb pain) occurred at a smaller incidence with the intermittent regimen.

We conclude that a 20 mg/day fluoride continuous regimen given as MFP plus calcium can decrease fracture rate also in patients with severe osteoporosis if given for sufficiently long periods (>3 years). However, a lower dose intermittent regimen might have an even better efficacy/safety ratio. Different studies are in progress to test both these regimens in combination with a bisphosphonate antiresorptive treatment.

Ringe, J.D., Osteoporosis International, Sept. 11-15,1998, vol. 8, #3, p.148