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Completed Phase 2 Interventional Results available

Investigation of the NMDA Antagonist Ketamine as a Treatment for Tinnitus

ClinicalTrials.gov ID: NCT03336398

Public ClinicalTrials.gov record NCT03336398. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.

ClinicalTrials.gov public records Last synced Sep 1, 2026, 3:56 PM EDT

Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.

Brief summary

Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.

Tinnitus, or ringing in the ears, is a very common problem that often accompanies hearing loss. It affects up to 1 in 10 adults, and about 30% of people who experience chronic tinnitus find it very distressing. In these patients, symptoms of depression and anxiety often accompany tinnitus and there are no approved treatments. Clinical trials are ongoing to test a glutamate NMDA receptor antagonist (called esketamine), which is injected into the inner ear. However, the preliminary results with this medication show that it only works for tinnitus that results from acute injury. It does not treat tinnitus resulting from progressive hearing loss. Research in humans and animals suggest that the neurotransmitters glutamate and GABA are important in the development and maintenance of tinnitus. This data shows that over-activation of the NMDA receptor and a decrease in GABA signaling in the brain play a crucial role. Previous studies show that ketamine, which an antagonist at the NMDA receptor, increases GABA levels in the brain in participants with depression. Thus, in this experiment, this study will test the effect of ketamine on tinnitus, since it blocks the NMDA glutamate receptor and increase GABA levels. Two groups of participants will be included in this study: those who experience distress (symptoms of anxiety or depression) with tinnitus and those who have tinnitus but do not experience distress. Each participant will receive both ketamine and placebo on different days. Magnetic Resonance Spectroscopy (MRS) scans will be

Study identification

NCT ID
NCT03336398
Recruitment status
Completed
Study type
Interventional
Phase
Phase 2
Enrollment
42 participants

Conditions and interventions

Conditions

Interventions

Drug

Eligibility (public fields only)

Age range
21 Years to 60 Years
Sex
All
Healthy volunteers
Healthy volunteers not accepted

This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.

Study timeline

Start date
Aug 31, 2019
Primary completion
Jun 16, 2023
Completion
Jun 30, 2024
Last update posted
Mar 24, 2026

2019 – 2024

United States locations

U.S. sites
1
U.S. states
1
U.S. cities
1
Facility City State ZIP Site status
1051 Riverside Drive New York New York 10032

Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.

About this trial record page

What this page shows
Public field values for ClinicalTrials.gov record NCT03336398, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
What this page does not do
No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
Where the data comes from
Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
Last refresh
Last update posted Mar 24, 2026 · Synced Sep 1, 2026

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Open the official record

The complete protocol, eligibility criteria, and contact information for NCT03336398 live on ClinicalTrials.gov.

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