Drug-induced taste and smell alterations: a case/non-case evaluation of an italian database of spontaneous adverse drug reaction reporting.

BACKGROUND: The frequency and clinical features of drug-related taste and/or smell impairments are currently unclear.

OBJECTIVE: The aim of this study was to identify major drug classes associated with taste and smell alterations reported to the Italian spontaneous adverse drug reaction (ADR) reporting database.

METHODS: The association between drug and altered taste or smell was investigated by case/non-case methodology. The reporting odds ratio (ROR) was used as a measure of disproportionality. Cases were defined as patients with at least one ADR related to taste or smell impairments. The non-cases included all patients without any ADRs related to taste or smell alterations.

RESULTS: According to the selection criteria, 52 166 reports were included in the analysis. Overall, 182 cases of drug-related taste and/or smell dysfunctions were identified. Statistically significant unadjusted RORs were reported for macrolides (n = 31; 7.1; 95% CI 4.8, 10.5), terbinafine (the only drug reported within the group of antimycotics belonging to the Anatomical Therapeutic Chemical class D01AE) [n = 17; 76.4; 95% CI 44.0, 132.6], fluoroquinolones (n = 15; 1.7; 95% CI 1.0, 2.8) and protein kinase inhibitors (n = 10; 4.0; 95% CI 2.1, 7.7). When RORs were adjusted for sex and age category, the disproportion remained statistically significant for all of the previously mentioned drug classes.

CONCLUSIONS: Taste and/or smell abnormalities are common, sometimes unexpected and often persistent complaints of patients during pharmacological treatments. Physicians should be aware of the impact of these ADRs on patients' quality of life.