Omeprazole (40 mg once daily in the morning) is significantly more effective than ranitidine (300 mg once daily in the morning) with respect to H. pylori eradication when used together with amoxycillin (750 mg three times a day) and metronidazole (500 mg three times a day) for a 7-day treatment period.

This randomized, multicentre, double-blind, double-dummy study compared the efficacy and safety of amoxycillin 1 g bd with amoxycillin 500 mg tds in 395 patients with a clinical diagnosis of acute exacerbation of chronic bronchitis (AECB). Patients were treated for 10 days and were assessed during therapy (days 3-5), after the end of therapy (days 12-15) and at follow up (days 28-35). In the intention-to-treat (ITT) population, clinical success rates at the end of therapy were 86.6% (162/187 patients) and 85.6% (161/188 patients) in the bd and tds group, respectively. In the per-protocol (PP) subgroup, the success rates were 89.1% (156/175) and 92.6% (150/162), respectively. The clinical recurrence rates at follow up were, in the ITT and PP populations, respectively, 14.2% (20/141) and 13.4% (18/134) in the bd group, and 12.6% (18/143) and 13.7% (18/131) in the tds group. The 95% confidence intervals (CI) confirmed the clinical equivalence of the two dosage regimens in the ITT and PP populations. Two hundred and nineteen patients from the clinically evaluable ITT population had at least one pathogen isolated at baseline and were evaluable for bacteriological efficacy. Bacteriological success at the end of therapy was obtained in 76.2% (83/109) of patients in the bd group, and 73.7% (81/110) of patients in the tds group (95% CI: -9 to 14%). The most frequently reported drug-related adverse events in the safety evaluable patients were gastrointestinal symptoms, which occurred in 11.2% (22/197) in the bd group and 11.6% (23/198) in the tds group. Amoxycillin 1 g bd is clinically and bacteriologically as effective as amoxycillin 500 mg tds in the treatment of AECB, and the two dosage regimens show a similar safety profile.

In this prospective randomized clinical study a total of 59 patients of both sexes (above 18 years of age) were enrolled. Thirty patients with acute sinusitis were randomly allocated to two treatment groups, one group receiving 1000 mg amoxicillin every 12 h for 10 days and the other group receiving 500 mg amoxicillin every 8 h for 10 days. The median concentration of amoxicillin in nasal secretions was 2.34 micrograms/ml in the 12-h administration group and 1.95 micrograms/ml in the 8-h administration group. Median bioavailability of antibiotic at 8-24 h did not show any statistical differences between the two treatment schemes [probability (Z) = 0.2]. Twenty-nine patients with chronic sinusitis were then randomly allocated to three groups, with patients receiving 1000 mg amoxicillin at 12, 8 or 6 h before nasal and/or sinus surgery was carried out. The mean amoxicillin concentrations in mucosal tissues removed intraoperatively ranged from 0.69 to 0.99 microgram/g samples. Statistical evaluation by analysis of variance did not show any statistically significant differences among the three treatment groups [probability (F) = 0.1705]. In all cases of acute and chronic sinusitis, amoxicillin concentrations exceeded minimum inhibitory concentration values for pathogens common in sinusitis. Our results indicate that 1000 mg amoxicillin administered twice daily produces tissue concentrations high enough to be clinically effective in patients with either acute or chronic sinusitis.