Phase 4
Completed N=40
Nitrous Oxide Treatment for Tinnitus
Source: ClinicalTrials.gov NCT03365011 ↗Enrolled (actual)
40
Serious AEs
0.0%
Results posted
Nov 2018
Primary outcomePrimary: Change in Tinnitus Functional Index (TFI) Score — -1.8; -2.5 score on a scale
◆ Published Evidence
Emerging
11citations · ~1 / year
Effect of Nitrous Oxide as a Treatment for Subjective, Idiopathic, Nonpulsatile Bothersome Tinnitus: A Randomized Clinical Trial.
Summary
Tinnitus is perception of sound without the presence of an external acoustic stimulus. Approximately 50 million Americans experience chronic tinnitus and of these, 10 million have bothersome tinnitus. The tinnitus research literature suggests that NMDA receptor antagonists may prove to be useful in reducing tinnitus. Nitrous oxide, a member of the NMDA receptor antagonist class, is a widely-used general anesthetic and sedative with a proven safety profile. The investigators hypothesized that the administration of nitrous oxide, an NMDA receptor antagonist, may be effective in treatment of tinnitus. The study design was a randomized placebo-controlled crossover trial.
Linked Publications
-
Effect of Nitrous Oxide as a Treatment for Subjective, Idiopathic, Nonpulsatile Bothersome Tinnitus: A Randomized Clinical Trial.
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY Change in Tinnitus Functional Index (TFI) Score |
-1.8; -2.5 | — |
| SECONDARY Change in Global Bothersome Scale (GBS) Score |
5; 2; 28; 34; 5; 2 | — |
| SECONDARY Patients' Global Impression of Change |
24; 20; 5; 10; 2; 2 | — |
Eligibility Criteria
Inclusion Criteria
- Adult men and women 18-65 years of age
- Subjective, unilateral or bilateral, non-pulsatile tinnitus scoring "Bothered more than a little but not a lot", "Bothered a lot", or "Extremely bothered" on the Global Bothersome scale
- Able to give informed consent
- Must be able to read, write, and understand English
Exclusion Criteria
- Bipolar disorder
- Schizophrenia
- Schizoaffective disorder
- Substance abuse or dependence (except for remote substance abuse or dependence with remission at least 1 year prior to the study and except for nicotine use disorders)
- Acute medical illness that may pose subject at risk during nitrous oxide administration
- Active psychotic symptoms
- Patients with significant pulmonary disease and/or requiring supplemental oxygen
- Contraindication against the use of nitrous oxide:
- Pneumothorax
- Bowel obstruction
- Middle ear occlusion
- Elevated intracranial pressure
- Chronic cobalamin and/or folate deficiency treated with folic acid or vitamin B12
- Pregnant patients
- Breastfeeding women
- Previous administration of NMDA-receptor antagonists (e.g., ketamine) within the last 3 months
- Tinnitus related to cochlear implantation, retrocochlear lesion, Meniere's Disease, or other known anatomic lesions of the ear or temporal bone
- Tinnitus related to a Workman's Compensation claim or litigation-related event that is still pending.
- Any medical condition, which, in the opinion of the PI, confounds study results or places the subject at greater risk
Data sourced from ClinicalTrials.gov (NCT03365011) and the linked publication. Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication. Informational only — not medical advice.