Sodium fluoride therapy in cochlear otosclerosis works by which primary mechanism?

• A Converting fluorapatite from hydroxyapatite, stabilizing the otospongiotic focus and reducing enzymatic activity ✓
• B Inhibiting osteoclast-mediated bone resorption
• C Promoting endolymph resorption by the endolymphatic sac
• D Blocking sodium channels in the stria vascularis

Explanation

Sodium fluoride stabilizes the otospongiotic foci by converting the metabolically active hydroxyapatite into the more stable fluorapatite crystal, reducing the enzymatic and osteoclastic activity of the spongiotic focus. It also inhibits alkaline phosphatase and lysosomal enzymes. It does NOT arrest established bone disease but may slow progression of the SNHL component. It is used in doses of 40-60 mg/day with calcium for cochlear otosclerosis without operative benefit.

Reference: Dhingra Diseases of Ear, Nose and Throat, 7th ed.

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Written and medically reviewed by the StethoPrep medical team.