Safety Pharmacology and Tinnitus

This work used publically available data from clinical trials to assess the outcomes of safety pharmacology regarding tinnitus reported during clinical trials or postmarketing surveillance. The data concerning adverse effects induced by prototype drugs for tinnitus was derived from ClinicalTrial.gov. Even though none of the prototype drugs for tinnitus has been approved yet, and despite only a small proportion of trials publishing results, the available data from five studies of four drugs suggest that at least one of these medications can also induce tinnitus. Additionally, evidence regarding tinnitus frequency reported by the SIDER database was analyzed. The analysis indicated that 26.7% of all drugs registered had tinnitogenic potential; however, more detailed information was available only for 110 drugs (7.7%). The data concerning the 110 drugs were extracted to analyze the classes of medicines associated with tinnitus induction. Based on the Anatomical Therapeutic Chemical (ATC) classification system of WHO, the following classes of drugs are particularly associated with tinnitus induction: medicines used to treat the cardiovascular system (C), anti-infectives of systemic use (J), antineoplastics and immunomodulating agents (L), and nervous system (N). Obtained information shows that tinnitus is a common adverse effect reported in the protocols of clinical studies within the entire spectrum of frequencies (frequent to rare). Tinnitus patients should cautiously use these medicines, and it would be advisable to report possible new cases during the postmarketing surveillance. Additionally, continuing safety pharmacology for tinnitus is essential when treating tinnitus patients pharmacologically and in patients chronically using potentially tinnitogenic medicines.