title: Short-course therapy of acute bacterial exacerbation of chronic bronchitis: a double-blind, randomized, multicenter comparison of extended-release versus immediate-release clarithromycin.
abstract: OBJECTIVE
  The objective of this study was to compare the efficacy and safety of two clarithromycin formulations given for 5 days to patients with acute bacterial exacerbation of chronic bronchitis (ABECB).
  
  
  METHODS
  This was a double-blind, randomized, multicenter study of ambulatory patients between 40 and 75 years of age with a medical history of chronic bronchitis, chronic obstructive pulmonary disease and a presumptive diagnosis of ABECB who met Anthonisen Type 1 criteria (increased dyspnea, increased sputum volume and increased sputum purulence). Eligible patients received a 5-day course of clarithromycin extended-release (ER) 500 mg once daily or clarithromycin immediate-release (IR) 250 mg twice daily. Clinical cure, bacteriological cure and pathogen eradication rates were determined at the end of therapy and at a follow-up visit.
  
  
  RESULTS
  Clinical cure rates were similar at the test-of-cure visit for evaluable patients in the clarithromycin ER group (97%, 298/307) and clarithromycin IR group (98%, 300/307) (95% CI (-3.2, 1.9)). The bacteriological cure rate was 89% and the pathogen eradication rate was 90% in both treatment groups. Resolution or improvement in cough, sputum production, sputum volume and sputum appearance was observed in > 90% of evaluable patients in each treatment group. The incidence of study drug-related adverse events was 6.6% (23/351) in the clarithromycin ER group and 5.4% (19/352) in the clarithromycin IR group. The most frequently occurring study drug-related adverse events were abdominal pain, diarrhea and taste perversion.
  
  
  CONCLUSIONS
  Clarithromycin ER 500 mg once daily for 5 days is equivalent to clarithromycin IR 250 mg twice daily for 5 days in treating adults with ABECB. Both regimens were effective in resolving clinical signs and symptoms of ABECB and eradicating the target pathogens, and were well tolerated.
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000494:pharmacology; D001424:Bacterial Infections / Q000188:drug therapy* / Q000382:microbiology; D029481:Bronchitis, Chronic / Q000188:drug therapy* / Q000382:microbiology; D017291:Clarithromycin / Q000008:administration & dosage* / Q000494:pharmacology; D003692:Delayed-Action Preparations; D004311:Double-Blind Method; D024881:Drug Resistance, Bacterial; D006801:Humans; D008875:Middle Aged; D010349:Patient Compliance; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D003692:Delayed-Action Preparations; D017291:Clarithromycin