People with long-COVID and breathlessness that affects daily life Infections and Infestations
Conditions
Interventions
A single dose of oral gefapixant (45 mg) tablet will be used as a mechanistic tool to investigate whether P2X3 receptors contribute to carotid chemoreflex hyperactivity in patients with long-COVID
We
Sponsors
University of Bristol
Eligibility
Sex/Gender
All
Age
18 Years to 75 Years
Inclusion criteria
Inclusion criteria: 1. 18-75 years old 2. Self-reported positive PCR or antibody test before vaccination 3. Not hospitalised for any COVID-19 infection 4. Breathlessness affecting their daily lives, measured by Modified Yorkshire COVID-19 Rehabilitation Scale (used in some long-COVID clinics)
Exclusion criteria
Exclusion criteria: 1. Body mass index =35 kg/m² 2. Diagnosed with severe asthma or uncontrolled asthma 3. Pregnancy/breastfeeding women 4. Ongoing requirement of oxygen therapy 5. Moderate anaemia (Hb 28 units/week) or use of illicit drugs 19. History of tobacco smoking within last 12 months 20. Inability to understand instructions given in English 21. Surgery under general anaesthesia within 3 months 22. History of stroke 23. Heart transplant 24. Coronary revascularisation 25. Haemodialysis or peritoneal dialysis 26. Participating in another study for an investigational medicinal product 27. Any contraindication to gefapixant or its derivatives, or severe drug allergies 28. Estimated glomerular filtration rate (eGFR) <30 ml/min
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Hypoxic ventilatory response (HVR) at rest measured using chemoreflex sensitivity, calculated as the increase in minute ventilation divided by the SpO2% (termed the hypoxic ventilatory response or HVR and expressed as L/min/SpO2%), at 2-3 hours after taking gefapixant or placebo | — |
Secondary
| Measure | Time frame |
|---|---|
| 1. Resting normoxic tidal volume measured with spirometry, 2-3 hours after taking gefapixant or placebo 2. Resting end-tidal pressure of carbon dioxide (PETCO2) measured with spirometry, 2-3 hours after taking gefapixant or placebo 3. Resting ratio of minute ventilation to carbon dioxide production (VE/VCO2) measured with spirometry, 2-3 hours after taking gefapixant or placebo 4. Resting dyspnoea measured using the visual analogue scale, 2-3 hours after taking gefapixant or placebo 5. Resting minute ventilation measured with spirometry, 2-3 hours after taking gefapixant or placebo 6. Resting breathing frequency measured with spirometry, 2-3 hours after taking gefapixant or placebo 7. Resting blood pressure measured continuously with Finapres finger blood pressure cuff, 2-3 hours after taking gefapixant or placebo 8. Resting heart rate measured continuously using a three-lead ECG, 2-3 hours after taking gefapixant or placebo 9. Minute ventilation measured using a face mask and gas analyser continuously (breath-by-breath) throughout exercise 10. Respiratory rate measured using a face mask and gas analyser continuously (breath-by-breath) throughout exercise 11. Oxygen consumption measured using a face mask and gas analyser continuously (breath-by-breath) throughout exercise 12. Dyspnoea score measured using the visual analogue scale every 2 minutes throughout exercise and at peak exercise | — |
Countries
England, United Kingdom
Contacts
Public ContactEmma Hart
Outcome results
None listed