Sudden hearing loss has been reported on standard interferon (IFN) alfa therapy. This is the first report on the occurrence of sudden hearing loss in six cases of chronic hepatitis C in temporal relation to treatment with pegylated (PEG)-IFN alfa-2a or -2b/ribavirin combination therapy.

Three patients were treated in an ongoing randomized placebo-controlled trial comparing the addition of 200 mg amantadine or placebo to the combination of 180 microgram PEG-IFN alfa-2a (Pegasys) /wk and 1-1.2 gram ribavirin/day (Copegus) in de novo patients infected with HCV genotype 1.

Sudden hearing loss and tinnitus developed on day 1 and after 4, 23, 25, 36, and 40 weeks of treatment, respectively.

Conclusions

Sudden hearing loss may occur in about 1% of patients on PEG-IFN/ribavirin combination therapy. This rate was not different to that observed in an untreated population.

Possible mechanisms involved include direct ototoxicity of IFN, autoimmunity, and hematological changes.

In contrast to published cases on auditory disability due to standard IFN, hearing loss did not fully resolve after discontinuation of therapy with PEG-IFN. On the other hand, symptoms did not worsen on continued treatment.

Therefore, the decision whether to continue or to stop the treatment when signs of ototoxicity appear is based on the clinical judgment of the treating physician.

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E Formann and others. Sudden Hearing Loss in Patients with Chronic Hepatitis C Treated with Pegylated Interferon/Ribavirin. American Journal of Gastroenterology 99(5): 873-877. May 2004.