Tocainide and tinnitus.  Clinical effect and site of action. 
Tocainide, an amine analogue of lidocaine, which can be taken orally, was tested on 9 patients with severe tinnitus.  6 patients responded to the drug.  In 4 patients the effect ceased after about 2 weeks despite continuous medication.  2 patients are still on this medication after more than 2 years.  The binding of tocainide to melanin was analysed in vitro and in vivo in rats.  It was concluded that the effect of tocainide on tinnitus is mediated by a peripheral mechanism possibly related to the accumulation on inner ear melanin.