1. Be able to discuss mechanism of the loss of smell due to the use of intranasal zinc gluconate gel. 2. Understand that zinc gluconate, applied to the human nose in available doses, produces permanent loss of smell in some patients by the same mechanism as that of zinc sulfate (historical control).
Methods
It has been shown that zinc gluconate gel squirted into the human nose reaches the olfactory cleft. Clinical endoscopic observations have evaluated the patency of the pathway from the external nasal opening to the olfactory cleft. Cadaver studies show that the gel reaches the olfactory cleft. Protein precipitate studies (albumin) presented here test the hypothesis that zinc ions from the gluconate salt produced pharmacodynamic changes in the same manner that other zinc salts do.
Results
These protein (albumin) studies show precipitation of the protein (albumin) in the same manner produced by zinc sulfate and other zinc salts, with a clear dose-response relationship, a precipitation that does not occur with similar salts with similar anions, lacking the zinc cation. A comparison of amounts of zinc ion per cm2 verified the olfactotoxic ED50 of the zinc gluconate, as compared to historical controls.
Conclusions
Zinc gluconate gel, applied to the human nose in available doses, produces permanent loss of smell in some patients by the same mechanism as that of zinc sulfate.
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