[Olfactory disorders due to medications: analysis and review of the literature]

Abstract

Introduction: Olfactory disorders caused by medicinal drug intake are an uncommon occurrence. However, such an etiology should be systematically taken into account and investigated, as olfactory loss may be reversible once the particular treatment has been stopped.

Current knowledge and key points: An analysis of the literature shows that of the large number of drugs that are apparently responsible for olfactory disorders, this adverse side effect has in fact only been observed in animal study populations, and no clinical case report has been made on the subject. The real toxicity to man is therefore only hypothetical. Of the 150,000 cases recorded in the pharmacovigilance centers in France, only 68 have reported olfactory complications (0.05% of cases), and only 22% of the medical files on this disorder reach a satisfactory level of plausibility. Cardiovascular drugs are mainly implicated in the development of olfactory disorders. Of these, certain drugs in particular should be mentioned: conversion enzyme (ACE) inhibitors which are responsible for taste disorders, some betablockers, and a calcium antagonist (a dihydropyridine derivative). Olfactory disorders have also been reported following administration of drugs used in anesthesia, in cancerology, endocrinology (carbimazole), in immunology (interferon), in the treatment of infectious diseases (ciprofloxacine, dioxycycline, terbinafine), and in rheumatology (D-penicillamine).

Future prospects and projects: It is frequently difficult to establish a direct relationship between drug exposure and an olfactory disorder, and it is often not easy to determine with any certainty the causative role of the drug in the development of this disorder.