First author [Ref.] | Drug | Dose | Trial duration | Reduction in exacerbations % |
Seemungal [28] | Erythromycin | 250 mg every 12 h | 1 yr | 35 |
Sethi [32] | Moxifloxacin | 400 mg·day−1 for 5 days every 2 months | 1 yr | 25 (46#) |
Calverley [40] | Fluticasone | 500 μg every 12 h | 3 yrs | 18 |
Kardos [60] | Fluticasone | 500 μg every 12 h | 1 yr | 35¶ |
Szafranski [38] | Budesonide | 320 μg every 12 h | 1 yr | 15 |
Calverley [40] | Salmeterol | 50 μg every 12 h | 3 yr | 15 |
Stockley [76] | Salmeterol | 50 μg every 12 h | 1 yr | 30 |
Dusser [45] | Tiotropium | 18 μg·day−1 | 1 yr | 27 |
Barr [46] | Tiotropium | 18 μg·day−1 | 4 yrs | 14+ |
Hubbard [59] | BFC | 320 μg every 12 h | 1 yr | 25 |
Calverley [40] | FSC | 500/50 μg every 12 h | 3 yrs | 25 |
Ferguson [63] | FSC | 250/50 μg every 12 h | 1 yr | 30.5 |
Zheng [69] | Carbocysteine | 1500 mg·day−1 | 1 yr | 25% |
Decramer [68] | NAC | 600 mg·day−1 | 3 yrs | 1 (21§) |
BFC: budesonide/formoterol combination; FSC: fluticasone/salmeterol combination; NAC: N-acetylcysteine. #: in patients with purulent or mucopurulent sputum at baseline; ¶: not compared with placebo, but with salmetrol alone in patients with forced expiratory volume in 1 s <50% pred; +: not compared with placebo, but with control group of usual medication; §: results in patients not treated with inhaled corticosteroids. As an example, a reduction in 25% means that in patients with 4 exacerbations per year, the frequency would reduce to 3 episodes per year.