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A Study on the Effect of Cilostazol in Patients With Chronic Tinnitus

Information source: Asan Medical Center
ClinicalTrials.gov processed this data on August 23, 2015
Link to the current ClinicalTrials.gov record.

Condition(s) targeted: Tinnitus

Intervention: Cilostazol (Drug); Placebo (Drug)

Phase: N/A

Status: Completed

Sponsored by: Jong Woo Chung

Official(s) and/or principal investigator(s):
Jong Woo Chung, M.D., Principal Investigator, Affiliation: Asan Medical Center


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.

Clinical Details

Official title: A Randomized, Prospective, Placebo-controlled Double-blind, Pilot Study on the Effect of Cilostazol for 4 Weeks in Patients With Chronic Tinnitus

Study design: Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Caregiver, Investigator), Primary Purpose: Treatment

Primary outcome: Change of the tinnitus handicap inventory (THI) score

Secondary outcome:

Changes of Quality of Life (SF-36) score

Change of the visual analogue scale (VAS) score

Detailed description: 1. Clinical research methods

- Determination of eligibility by history taking, physical examination, pure tone

audiometry, speech audiometry, and distortion product otoacoustic emission test.

- Randomization by random sequence generation

- Administration : cilostazol 100mg Bid 4 weeks for the study group and placebo

tablet Bid 4 weeks for the control group.

- Evaluation battery: questionnaires (tinnitus handicap inventory, visual analogue

scale, Quality of life SF-36)

- Time of evaluation : pre-administration, 2 weeks after administration, 4 week

after administration

- Monitoring of side effects

2. Evaluation of treatment response - Statistical analysis of scores of questionnaires

using SPSS K12. 0 (paired t-test for changes of each group and Mann-Whitney U test for comparing the mean scores of two groups)


Minimum age: 20 Years. Maximum age: N/A. Gender(s): Both.


Inclusion Criteria:

- Adults of age over 19

- Unilateral or bilateral tinnitus

- Chronic tinnitus lasting more than 3 months

- Initial visual analogue scale of tinnitus >3

Exclusion Criteria:

- Conductive hearing loss on pure tone audiometry

- Associated other inner ear diseases such as Meniere's disease

- Objective or pulsatile tinnitus

- Contraindication to anti-platelet drug

- Any cardiac disease

- Bleeding tendency and major operation within 3 months

- Breastfeeding

- Pregnancy

Locations and Contacts

Asan Medical Center, Seoul 138-736, Korea, Republic of
Additional Information

Institutional Review Board of Asan Medical Center

Related publications:

Mazurek B, Haupt H, Szczepek AJ, Sandmann J, Gross J, Klapp BF, Kiesewetter H, Kalus U, Stöver T, Caffier PP. Evaluation of vardenafil for the treatment of subjective tinnitus: a controlled pilot study. J Negat Results Biomed. 2009 Feb 17;8:3. doi: 10.1186/1477-5751-8-3.

Ye YL, Shi WZ, Zhang WP, Wang ML, Zhou Y, Fang SH, Liu LY, Zhang Q, Yu YP, Wei EQ. Cilostazol, a phosphodiesterase 3 inhibitor, protects mice against acute and late ischemic brain injuries. Eur J Pharmacol. 2007 Feb 14;557(1):23-31. Epub 2006 Nov 10.

Starting date: July 2011
Last updated: May 21, 2014

Page last updated: August 23, 2015

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