Twice daily dosage of bacampicillin in chronic bronchitis. A double-blind study.

Three groups of patients (total 48) with acute exacerbations of chronic bronchitis were treated orally for 10 days, in a double-blind clinical trial, with bacampicillin (an ampicillin ester) 1600 mg twice daily, 800 mg three times daily and oral ampicillin 1000 mg three times daily. Most exacerbations were caused by Haemophilus influenzae or Streptococcus pneumoniae. Clinical and bacteriological results were significantly more favourable in the two bacampicillin-treated groups. Both drugs were generally well tolerated. Serum and sputum ampicillin assays after the first dose showed higher and earlier peak levels after bacampicillin. Only after bacampicillin did the sputum levels regularly exceed the ampicillin M.I.C. for the Haemophilus influenzae strains. After the 1600 mg and 800 mg dose these levels averaged 0.85 and 0.41 mg/l respectively. One third of the Haemophilus influenzae strains studied required more than 0.25 mg/l ampicillin for inhibition of growth. Bacampicillin 1600 mg twice daily appears to be an effective and safe treatment for most episodes of acute exacerbations of chronic bronchitis.