Question:hard
All of the following statements about sodium fluoride in otosclerosis are true, except:
All of the following statements about sodium fluoride in otosclerosis are true, except:
Show Hint
Sodium fluoride hardens bone and curbs resorption, so a statement that it blocks bone formation is the odd one out.
Updated On: Jun 24, 2026
- Acts by inhibiting proteolytic enzymes in the cochlea
- Acts by inhibiting osteoblastic activity
- Is contraindicated in chronic nephritis
- Is indicated in patients with a positive Schwartze sign
Show Solution
The Correct Option is B
Solution and Explanation
This is a negative stem, so the task is to find the one wrong claim about sodium fluoride therapy in otosclerosis. Start from what the drug is meant to do. Active otosclerosis is a phase of bone breakdown and immature spongy bone formation around the stapes and cochlea. Fluoride is used to calm this activity down and harden the bone.
The first option says it inhibits proteolytic enzymes in the cochlea. That is correct; part of the rationale for fluoride is suppressing the lytic enzyme activity that drives otospongiosis. The third option says it should be avoided in chronic nephritis; that is also correct because fluoride clears through the kidneys and accumulates in renal impairment, so it is contraindicated there and in pregnancy. The fourth option ties treatment to a positive Schwartze sign, the pink flush over the promontory that marks active hyperaemic disease; since fluoride is given precisely for active otosclerosis, this too is true.
That leaves the claim that fluoride works by inhibiting osteoblastic activity. This is the false statement. Fluoride encourages bone formation and maturation rather than blocking the bone-forming osteoblasts; its inhibitory action is directed at the resorptive, osteoclastic and enzymatic side of the disease. Because the question asks for the exception, this wrong mechanism is the answer.
\[\boxed{\text{Acts by inhibiting osteoblastic activity (false)}}\]
The first option says it inhibits proteolytic enzymes in the cochlea. That is correct; part of the rationale for fluoride is suppressing the lytic enzyme activity that drives otospongiosis. The third option says it should be avoided in chronic nephritis; that is also correct because fluoride clears through the kidneys and accumulates in renal impairment, so it is contraindicated there and in pregnancy. The fourth option ties treatment to a positive Schwartze sign, the pink flush over the promontory that marks active hyperaemic disease; since fluoride is given precisely for active otosclerosis, this too is true.
That leaves the claim that fluoride works by inhibiting osteoblastic activity. This is the false statement. Fluoride encourages bone formation and maturation rather than blocking the bone-forming osteoblasts; its inhibitory action is directed at the resorptive, osteoclastic and enzymatic side of the disease. Because the question asks for the exception, this wrong mechanism is the answer.
\[\boxed{\text{Acts by inhibiting osteoblastic activity (false)}}\]
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