A Study on the Effect of Cilostazol in Patients With Chronic Tinnitus
Status:
Completed
Trial end date:
2013-06-01
Target enrollment:
Participant gender:
Summary
1. Overview of tinnitus Tinnitus is a noisy sound which is perceived without any external
sound source. According to the survey of the US, 10-20% of adult have the symptom of
tinnitus and 3-5% of tinnitus patients have severe discomfort of daily life. Severe
tinnitus can result in psychiatric problems such as depression and anxiety disorders.
Enhancement of environmental sound, hearing aids, sound generators, cognitive therapy,
transcranial magnetic therapy, and drug therapy have been tried for treatment of
tinnitus. Nitric oxide(NO) is a well-known neurotransmitter acting as a vasodilator
through regulation of production of cyclic guanosine monophosphate(cGMP) and can be
found in various sites of cochlea. It is reported that cGMP enhances activity of protein
kinase A (PKA), a mediator of platelet aggregation inhibition and vasodilatation and
results in increase of vascular flow.
2. Characteristics of the clinical research drug, cilostazol Cilostazol inhibits
phosphodiesterase type 3 (PDE3) selectively and increases amount of cAMP by inhibition
of degradation of cyclic adenosine monophosphate(cAMP). cAMP again by increasing the
active form of PKA suppress the production of blood clots and increase blood flow by
expanding blood vessels. Anti-platelet activity and vasodilatation effect of cilostazol
have been used for improvement of diabetic peripheral vascular disorders and suppression
of stroke recurrence. Previous studies reported that by increasing the activity of NO
and PKA, the blood flow of stria vascularis and cochlear hair cells can be improved.
These studies implies that cilostazol, which causes inhibition of PDE3 and increase of
PKA, can have a potential effect on improvement of tinnitus by increase of blood flow to
peripheral cochlear cells. Thus, we hypothesized that cilostazol, which has been widely
used for enhancing peripheral blood flow, can bring improvement of tinnitus by causing
better peripheral blood flow of cochlea.
3. The aim of the study We planned this study to validate the assumptions of the
background. The aim of our study is whether administration of cilostazol can improve
tinnitus in terms of subjective degree of symptoms in chronic tinnitus patients.