NCT05947643

Smell in COVID-19 and Efficacy of Nasal Theophylline (SCENT 3)

Smell in COVID-19 and Efficacy of Nasal Theophylline 3

• Status: Completed
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 77 (actual)
• Sponsor: Washington University School of Medicine · Academic / Other
• Sex: All
• Age: 18 Years – 75 Years
• Healthy volunteers: Not accepted

Summary

The purpose of this Phase II trial is to test the effectiveness of intranasal theophylline irrigations for the treatment of COVID-19 related smell dysfunction. The investigators will compare the effect of theophylline nasal rinses versus placebo nasal rinses on smell symptoms. Participants will be asked to rinse their nose with a medication or placebo capsule dissolved in saltwater twice daily for 12 weeks and fill out surveys about smell before, during, and at the end of treatment. This study will also be used to describe adverse effects related to intranasal theophylline irrigation.

Detailed description

COVID-related olfactory dysfunction (OD) is a major symptom of infection with SARS-COV-2, affecting up to 80% of those with COVID-19. While research on the pathogenesis is ongoing, a significant subset is expected to suffer from long-term OD. The investigators seek to test intranasal theophylline nasal irrigation as a potential therapeutic option for treatment of COVID-related OD lasting over 3 months. Theophylline has been shown to improve outcomes in post-viral OD in pilot studies, and initial data suggests therapeutic benefit in patients with post-COVID OD with minimal systemic absorption. The primary hypothesis is that theophylline irrigation will be more effective than placebo saline irrigation for COVID-19 related OD symptoms. The use of intranasal theophylline will have minimal adverse effects.

Conditions

• COVID-19

Interventions

Type	Name	Description
DRUG	theophylline	capsules dissolved in intranasal irrigation
DRUG	Placebo	identical-appearing lactose capsules dissolved in intranasal irrigation

Timeline

• Start date: 2022-11-22
• Primary completion: 2025-04-24
• Completion: 2025-08-04
• First posted: 2023-07-17
• Last updated: 2025-08-20
• Results posted: 2025-08-20

Locations

1 site across 1 country: United States

Regulatory

• FDA-regulated drug study