Mean (SD) baseline characteristics
| Erythromycin (n=15) | Placebo (n=15) | |
| No of women | 13 | 11 |
| Age, years | 63 (9) | 61 (9) |
| Duration of cough, years | 12 (4.2) | 11.1 (4.8) |
| Body mass index, kg/m2 | 27.5 (4.6) | 26.1 (4.9) |
| Percentage predicted FEV1 | 95 (10) | 96 (10) |
| FEV1/FVC | 0.77 (0.07) | 0.76 (0.04) |
| No of coughs in 24 h* | 389 (0.33) | 525 (0.33) |
| Total cells/g of selected sputum | 3.3×106 (1.9×106) | 3.1×106 (2.5×106) |
| Percentage sputum neutrophils | 68 (15) | 65 (26) |
| Percentage sputum eosinophils* | 0.6 (0.4) | 0.54 (0.37) |
| Sputum IL-8 (ng/ml)* | 9.15 (0.27) | 12.11 (0.58) |
| Bacterial CFU/ml* | 47 (0.25) | 29 (0.28) |
| C2 (μmol/l)* | 1.1 (0.69) | 0.62 (0.91) |
| C5 (μmol/l)* | 2.88 (0.55) | 4.17 (0.83) |
| LCQ score | 11.65 (1.97) | 11.86 (2.95) |
| Cough VAS (mm) | 57 (18) | 52 (17) |
↵* Geometric mean (log SD).
CFU, bacterial colony forming units; C2 and C5, concentration of capsaicin required to cause two and five coughs; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; IL-8, interleukin 8; LCQ, Leicester cough questionnaire; VAS, cough visual analogue score.