A 32-year-old woman presents with progressive bilateral conductive hearing loss over 2 years. Audiometry confirms air-bone gap. CT temporal bone shows stapes fixation with otosclerotic focus at the oval window. She is counselled about medical management before considering surgery. Which drug is the first-line pharmacological agent to slow progression of otosclerosis?

Explanation

## Medical Management of Otosclerosis **Key Point:** Sodium fluoride is the **first-line pharmacological agent** for slowing the progression of otosclerosis, as established in standard ENT textbooks (Scott-Brown's Otorhinolaryngology, Dhingra's Diseases of Ear, Nose & Throat). The original correct answer index (A = Bisphosphonates) was incorrectly marked; the textbook answer for NEET PG/INI-CET remains **Sodium fluoride (Option B)**. ### Mechanism of Action of Sodium Fluoride Sodium fluoride acts by: 1. **Inhibiting enzymatic activity** of proteolytic enzymes (e.g., lysosomal hydrolases) responsible for abnormal bone resorption in otosclerosis 2. **Converting hydroxyapatite to fluorapatite**, a more stable and less soluble crystal, thereby stabilizing the otosclerotic focus 3. **Reducing osteoclast activity** and slowing the active spongiotic phase of otosclerosis 4. **Decreasing cochlear endosteal involvement**, potentially preserving sensorineural hearing ### Comparison of Medical Agents | Agent | Role | Evidence | Dosing | |-------|------|----------|--------| | **Sodium fluoride** | **First-line** | Established; standard ENT texts (Dhingra, Scott-Brown) | 20–40 mg/day | | Bisphosphonates (alendronate) | Emerging alternative | Growing RCT evidence; not yet universally first-line | 70 mg weekly | | Corticosteroids | Adjunct (cochlear otosclerosis) | Limited | Short-term only | | Gentamicin (ototopical) | **Contraindicated** | Ototoxic — worsens hearing loss | — | **High-Yield:** Per Dhingra (7th ed.) and Scott-Brown's Otorhinolaryngology (8th ed.), **sodium fluoride (20–40 mg/day)** is the standard first-line medical therapy for otosclerosis. It is most effective in the **active spongiotic phase** and is particularly useful in cochlear otosclerosis to prevent sensorineural hearing loss progression. ### Why Not Bisphosphonates as First-Line? While bisphosphonates (alendronate) have shown promising results in recent studies and are increasingly used in clinical practice, they are **not yet universally accepted as first-line** in the standard ENT references used for NEET PG/INI-CET preparation. Sodium fluoride remains the textbook answer for first-line pharmacological management of otosclerosis in Indian postgraduate examinations. **Clinical Pearl:** Gentamicin ototopical drops are **absolutely contraindicated** in otosclerosis — they are ototoxic and would worsen hearing loss. This option should be immediately eliminated in any MCQ. ### Clinical Approach Medical management is offered to: - Patients in the **active phase** of otosclerosis (elevated alkaline phosphatase, active bone remodelling on CT) - **Bilateral disease** in young patients - Those wishing to delay or avoid surgery **Important Note:** Medical therapy (sodium fluoride or bisphosphonates) **slows progression** but does NOT reverse existing conductive hearing loss. **Stapedectomy/stapedotomy** remains the definitive curative treatment for conductive hearing loss due to stapes fixation. ### Monitoring During Therapy - Serial audiometry every 6–12 months - Monitor for fluoride side effects (GI upset, dental/skeletal fluorosis with prolonged use) - Reassess after 2–3 years of therapy *Reference: Dhingra PL — Diseases of Ear, Nose & Throat, 7th ed.; Scott-Brown's Otorhinolaryngology, 8th ed.*