Fluoride bioavailability from slow-release sodium fluoride given with calcium citrate

Area of Science:

• Pharmacology
• Biochemistry

Background:

• Slow-release sodium fluoride is used for bone health.
• Calcium citrate is a common calcium supplement.
• Understanding drug interactions is crucial for effective treatment.

Purpose of the Study:

• To investigate the clinical pharmacology of slow-release sodium fluoride.
• To examine the effects of calcium citrate and meals on sodium fluoride absorption and disposition.
• To determine the therapeutic window for long-term sodium fluoride administration.

Main Methods:

• Acute and long-term studies involving oral administration of slow-release sodium fluoride.
• Concurrent administration with calcium citrate or a meal.
• Measurement of serum fluoride concentrations over time (Cmax, Tmax, T1/2, AUC).

Main Results:

• Calcium citrate and meals reduced the peak serum fluoride concentration (Cmax) and the area under the curve (AUC) of slow-release sodium fluoride.
• Calcium citrate did not alter the time to peak concentration (Tmax) or the elimination half-life (T1/2).
• Meals increased Tmax but did not significantly affect T1/2.
• Long-term administration (25 mg twice daily) with calcium citrate maintained serum fluoride levels within the proposed therapeutic window (95-190 ng/ml).

Conclusions:

• Calcium citrate and meals significantly decrease the absorption and peak serum levels of slow-release sodium fluoride.
• The pharmacokinetic profile (Tmax, T1/2) of sodium fluoride is largely unaffected by calcium citrate.
• Co-administration with calcium citrate allows for sustained therapeutic serum fluoride concentrations during long-term treatment.