Furosemide Distinguishes Central and Peripheral Tinnitus.

The response of patients with tinnitus to the suppressive effects of IV furosemide is about 50%. Since furosemide is a drug without known effects on the central nervous system but with well documented effects in the auditory periphery, we hypothesized that it suppressed tinnitus of peripheral origin and that the response rate was due to that selectivity. To test this hypothesis we recruited 14 patients with unilateral tinnitus who had previously undergone either a labyrinthectomy or acoustic neuroma removal in the complaint ear. Tinnitus in these patients would most likely be of central origin. The first 12 patients tested were negative in response to IV furosemide as compared to the 50% response rate already documented. The last two patients had acoustic neuromas removed and were positive to IV furosemide, meaning that their tinnitus was suppressed. Examination of the case records of these latter two patients revealed that their cochlear portion of the VIIIn had been spared during surgery. We therefore suggest that IV furosemide selectively suppresses tinnitus of peripheral etiology.