New Hope for Depression Trial

A Repurposed Solvent Targets Persistent Tinnitus After COVID-19

A new clinical trial is investigating an unconventional treatment for persistent, treatment-resistant tinnitus linked to long-COVID or COVID-19 vaccination. The study will test whether a dual-route therapy based on dimethyl sulfoxide (DMSO) can reduce the burden of a symptom that has defied standard treatments for many patients. Tinnitus, the perception of sound without an external source, has emerged as a significant complaint in post-acute sequelae of SARS-CoV-2 (PASC) and post-vaccine injury, with few effective options.

How the 30-Day DMSO Intervention Works

The study design is a single-arm, open-label pilot. All 20 enrolled participants will receive the same 30-day treatment regimen. The dual-route approach involves two pharmacy-compounded products: a DMSO-based otic liquid for instillation into the ear canal every four days, and a DMSO-based transdermal cream applied to the skin around the ears and upper neck once daily at bedtime.

Researchers define success as at least half of the participants (50%) achieving a 50% or greater reduction in their score on the Tinnitus Handicap Inventory (THI) from the study’s start to Day 30. The team will also track secondary measures including changes in perceived tinnitus loudness and annoyance, impacts on sleep and concentration, related symptoms like headache and vertigo, and any adverse events. Follow-up continues remotely for a full year using electronic questionnaires.

Who is Eligible to Participate

Participation is limited to a specific subset of tinnitus patients. Eligible adults must be between 18 and 70 years old and have chronic, non-pulsatile tinnitus for at least six months. Their tinnitus must be bothersome, with a THI score of 20 or higher.

Critically, they must have a documented history of either long-COVID (PASC) or post-COVID-19 vaccine injury, with their tinnitus either starting or getting clearly worse in temporal connection to that event. All potential participants must have tried and failed at least two prior standard tinnitus therapies, such as sound therapy, cognitive behavioral therapy, antidepressants, or steroids. The trial excludes individuals with pulsatile tinnitus, certain ear conditions, or a history of specific psychiatric disorders.

The Scientific Rationale for Using DMSO

The choice of dimethyl sulfoxide (DMSO) is based on its unique pharmacological profile and historical reports. DMSO is an organic solvent derived from wood pulp. It has documented anti-inflammatory, antioxidant, and vasodilatory properties. It also acts as a penetration enhancer, potentially helping other therapeutic agents reach target tissues.

The trial’s protocol notes an open-label study from the 1970s which reported that DMSO-based formulations, when combined with other agents, improved or resolved subjective tinnitus in most treated patients. Modern theory suggests tinnitus in long-COVID and post-vaccine contexts may involve neuroinflammation, microvascular dysfunction, and oxidative stress in auditory pathways. DMSO’s properties could theoretically address these mechanisms, but this has not been systematically studied in these modern patient populations using current compounding standards.

Current Trial Status and Potential Impact

This trial, identified as NCT07567274, is currently listed as NOT_YET_RECRUITING. It is a Phase 2 pilot study aiming to enroll approximately 20 participants. After an initial in-person otolaryngology evaluation, all study visits and data collection will occur via telemedicine, a design choice that may improve accessibility for patients.

If successful, this pilot could provide the first controlled data on the use of compounded DMSO therapy for refractory tinnitus in patients with long-COVID or post-vaccine injury. Positive results would support the need for larger, placebo-controlled trials. For patients who have found no relief from existing options, this research represents a direct investigation into a potential new pharmacological approach for a debilitating and otherwise untreatable symptom.

This article is for informational purposes only. Consult a qualified professional for personalised advice.

Source:
DMSO Dual-Route Therapy for Refractory Tinnitus in Long-COVID and Post-COVID-19 Vaccine Injury (ClinicalTrials.gov: NCT07567274)