Fig. 1From: The P2X3 receptor antagonist filapixant in patients with refractory chronic cough: a randomized controlled trialStudy design and study procedures. Patients were randomized either to the treatment sequence ‘active drug followed by placebo’ or to the sequence ‘placebo followed by active drug’. Doses of filapixant or placebo were administered twice daily for 4 days at each dose step. On D3, 10, 17, and 24, the patient stayed at the clinical unit until about 6 h after the morning dose and returned on the next morning. PK blood samples were taken predose and 1, 2, 4, 6, and 12 h postpose. D…, day number …; LCQ, Leicester Cough Questionnaire; PK, pharmacokinetic(s); VAS, visual analog scaleBack to article page