Background: Medications administered to geriatric patients can account for their taste dysfunction. First and second generation antihistamines have been claimed to cause changes in taste perception. Therefore, this study investigated the effect of first and second-generation antihistamines on the ultrastructure of taste buds and lingual papillae of rats' tongues.
Methodology: Twelve adult male albino rats were randomly distributed into three groups. Control group: rats received distilled water daily, Histoloc group: rats received 4.8 mg/kg promethazine hydrochloride in distilled water daily and Zyrtec group: rats received 3 mg/kg of Cetirizine dihydrochloride in distilled water daily. After three weeks, all rats were euthanized and Tongues were dissected into two parts, two halves. Specimens from the right halves of the tongue were prepared for Hematoxylin & Eosin stain for histological and histomorphometric evaluation. While specimens from the left halves were used to measure caspase-3 and inducible nitric oxide synthase gene expression by qRT-PCR.
Results:
Histological examination of Histoloc and Zyrtec groups revealed distortion of normal fungiform papilla morphology with marked areas of degeneration in the taste bud. Although caspase-3 and inducible nitric oxide synthase revealed a statistically significant increase in gene expression in Zyrtec and Histoloc groups as compared to the control, the difference between Zyrtec and Histoloc was not significant.
Conclusion:
First and second-generation antihistamines resulted in various degenerative changes in rats' lingual papillae and taste buds. However, these effects were more pronounced with antihistamines of the first generation than those of the second.