Pharmacoeconomic analysis of selected antibiotics in lower respiratory tract infection.

An interactive pharmacoeconomic model was designed to evaluate the effects of clinical response and adverse drug events on the comparative cost and cost-effectiveness of a relatively new antibiotic, clarithromycin, compared with those of six other antibiotics used to treat community-acquired lower respiratory tract infection. The cost and cost-effectiveness analyses were based don 12 randomized, double-blind, controlled clinical trials conducted between 1987 and 1992 in regionally distributed outpatient clinics in the United States. The trials enrolled a total of 2377 patients. Of the 2377, 1102 patients were treated for acute exacerbation of chronic bronchitis, 591 for pneumonia, and 201 for either of the two conditions. Safety data for one of the antibiotics was obtained from a trial of patients with sinusitis (N = 483). The antibiotics included in the analysis were amoxicillin/clavulanate, ampicillin, cefaclor, cefixime, cefuroxime, clarithromycin, and erythromycin. The main outcome measures were the costs of resources to achieve a clinical response, costs related to managing adverse drug events, and costs of antibiotic treatment from the perspective of managed care. The mean total cost per episode ranged from approximately $137 to $267. The drug acquisition cost typically contributed a small amount to the overall cost. For the cost-effectiveness analysis, in which complication-free cure was used as a proxy for patient satisfaction, the range of mean cost per complication-free cure varied from approximately $307 for clarithromycin to $612 for cefaclor. When ranked from most to least cost-effective, the order was as follows: clarithromycin, cefixime, amoxicillin/clavulanate, erythromycin, cefuroxime, ampicillin, and cefaclor. The costs associated with clinical management (including treatment failure) and managing adverse drug events significantly contribute to the total cost and cost-effectiveness of antibiotics in the outpatient setting. Cost-effectiveness analyses are valuable in analyzing the various costs associated with the treatment of lower respiratory tract infection (acute exacerbation of chronic bronchitis or pneumonia) and may be useful tools for physicians managing patients, members of pharmacy and therapeutics committees developing formularies, and medical staff implementing practice guidelines.