title: Eradication of pathogens from the nasopharynx after therapy of acute maxillary sinusitis with low- or high-dose amoxicillin/clavulanic acid.
abstract: The growing resistance of Streptococcus pneumoniae to penicillin can be overcome by increasing the dose of the penicillin administered. This generated the recommendation that the adult dose of amoxicillin for the treatment of acute maxillary sinusitis (AMS) be increased from 1.5 g/day to 4.0 g/day. The objective of this study was to investigate whether the higher dose of amoxicillin is more effective than the previously recommended dose in eradicating S. pneumoniae from the nasopharynx of patients who present with AMS. Nasopharyngeal cultures obtained from 58 patients with AMS were studied: 30 received amoxicillin 1.5 g/day given in divided doses three times a day for 10 days (amoxicillin/clavulanic acid 4:1 formulation) and 28 were treated with amoxicillin 4.0 g/day given in divided doses twice a day for 10 days (amoxicillin/clavulanic acid 16:1 formulation). Seventy-one potentially pathogenic organisms were isolated: S. pneumoniae (27 isolates), Haemophilus influenzae non-type b (25), Moraxella catarrhalis (5), Streptococcus pyogenes (5) and Staphylococcus aureus (9). The number of S. pneumoniae isolates in the 1.5 g/day group was reduced from 14 to 9 (2 intermediately resistant and 3 highly resistant). In contrast, the number of S. pneumoniae isolates in the 4.0 g/day group was reduced from 13 to 2 (1 highly resistant) (P<0.05). No differences were noted in the eradication rate of other groups of isolates, which were all susceptible to amoxicillin/clavulanic acid. These data illustrate the superiority of 4.0 g/day amoxicillin/clavulanic acid compared with 1.5 g/day amoxicillin/clavulanic acid in the eradication of S. pneumoniae from the nasopharynx.
authors.affiliation: Department of Pediatrics, Georgetown University School of Medicine and Alachua General and North Florida Regional Hospitals, Gainesville, FL, USA. ib6@georgetown.edu
authors.forename: Itzhak
authors.initials: I
authors.lastname: Brook
authors.forename: Perry A
authors.initials: PA
authors.lastname: Foote
authors.forename: Jeffrey N
authors.initials: JN
authors.lastname: Hausfeld
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D019980:Amoxicillin-Potassium Clavulanate Combination / Q000008:administration & dosage*; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D001424:Bacterial Infections / Q000188:drug therapy* / Q000382:microbiology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006192:Haemophilus Infections / Q000188:drug therapy / Q000382:microbiology; D006193:Haemophilus influenzae; D006801:Humans; D008297:Male; D015523:Maxillary Sinusitis / Q000188:drug therapy* / Q000382:microbiology*; D008875:Middle Aged; D001936:Moraxella catarrhalis; D045828:Moraxellaceae Infections / Q000188:drug therapy / Q000382:microbiology; D009305:Nasopharynx / Q000382:microbiology; D011008:Pneumococcal Infections / Q000188:drug therapy / Q000382:microbiology; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000382:microbiology; D013290:Streptococcal Infections / Q000188:drug therapy / Q000382:microbiology; D013297:Streptococcus pyogenes
chemical_list: D000900:Anti-Bacterial Agents; D019980:Amoxicillin-Potassium Clavulanate Combination