Rationale for treating community-acquired lower respiratory tract infections with amoxicillin/sulbactam combination through pharmacodynamic analysis in the setting of aminopenicillin-resistant organisms.

Abstract

In order to establish a rationale for treating community-acquired lower respiratory tract infections, we assess here the pharmacodynamics of amoxicillin/sulbactam, 500mg/500mg, a formulation marketed in Argentina since 1988 and currently available in 17 countries, against the major pathogens, in comparison with that of a novel formulation (875mg/125mg, see J Chemother 2000; 12: 223-227). In time-kill studies, both bactericidal and inhibitory activity were seen in the 1.5- and 6-h sera, obtained from 12 volunteers after a single oral dose, against both a penicillin-susceptible and an -intermediate Streptococcus pneumoniae strain, as well as against Moraxella catarrhalis and a beta-lactamase-negative Haemophilus influenzae strain. Only the 1.5-h sera proved bactericidal against a penicillin-resistant S. pneumoniae strain (MIC, 2 microg/ml) and a beta-lactamse-positive H. influenzae isolate. This study suggests that amoxicillin/sulbactam (500mg/500mg) is still a suitable option for treating community-acquired lower respiratory tract infections, allowing a b.i.d. dosing schedule. Caution should be taken with pneumonia caused by beta-lactamase-positive H. influenzae or penicillin-resistant (MIC > or =2 microg/ml) S. pneumoniae isolates. Either shorter dosing intervals (t.i.d.) or a higher amoxicillin content in the formulation (i.e. 875 mg) may be required in these situations.

• Authors: C Bantar, F Nicola, L Fernandez Canigia, H J Arenoso, J Soutric, M Montoto, M Blanco, J Smayevsky, A Jasovich
• Journal: Journal of chemotherapy (Florence, Italy) (J Chemother) Vol. 13 Issue 4 Pg. 402-6 (Aug 2001) ISSN: 1120-009X [Print] England
• PMID: 11589483 (Publication Type: Journal Article)

Chemical References

• Amoxicillin
• Sulbactam

Topics

• Administration, Oral
• Adult
• Amoxicillin (pharmacology)
• Community-Acquired Infections (drug therapy, microbiology)
• Drug Therapy, Combination (pharmacology)
• Female
• Haemophilus influenzae (drug effects, isolation & purification)
• Humans
• Male
• Microbial Sensitivity Tests
• Moraxella catarrhalis (drug effects, isolation & purification)
• Penicillin Resistance
• Pneumonia, Bacterial (drug therapy, microbiology)
• Serum Bactericidal Test
• Streptococcus pneumoniae (drug effects, isolation & purification)
• Sulbactam (pharmacology)