Effects of antibiotic treatment in the subset of common-cold patients who have bacteria in nasopharyngeal secretions.
BACKGROUND
Upper-respiratory-tract infection is one of the main causes of overuse of antibiotics. We have found previously that bacteria such as Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae can be isolated from the nasopharyngeal secretions of a substantial proportion of adults with upper-respiratory-tract infections. We have assessed the efficacy of co-amoxiclav in patients with common colds but no clinical signs of sinusitis or other indications for antibiotics.


METHODS
Between January, 1992 and March, 1994, 314 patients who presented to our outpatient clinic with common colds were enrolled in the double-blind, placebo-controlled study. They were randomly assigned 5 days' treatment with co-amoxiclav (375 mg three times daily) or identical placebo. Clinical examinations were done at enrolment and on day 5-7 to assess outcome (cured, persistent symptoms, worse symptoms). Seven patients were excluded after randomisation, seven did not have nasopharyngeal aspiration, and 12 did not return for followup assessment.


RESULTS
Of 300 patients with nasopharyngeal aspirates, 72 had negative bacterial cultures, 167 had cultures positive only for bacteria unrelated to respiratory infections, and 61 had cultures positive for H influenzae, M catarrhalis, or S pneumoniae. At 5-day follow-up of these culture-positive patients, the distribution of outcome was significantly better among co-amoxiclav-treated (n=30) than placebo-treated (n=28) patients (cured 27 vs 4%; persistent symptoms 70 vs 60%; worse symptoms 3 vs 36%; p=0.001). Patients on co-amoxiclav also scored their symptoms significantly lower than patients on placebo (p=0.008). Among culture-negative patients (n=230), the outcome distribution did not differ between the treatment groups (p=0.392).


CONCLUSIONS
The majority of patients with upper-respiratory-tract infection do not benefit from antibiotics and side-effects are frequent. However, for the subgroup whose nasopharyngeal secretions contain H influenzae, M catarrhalis, or S pneumoniae, antibiotics are clinically beneficial.
Kaiser
L
L
Division of Infectious Diseases, University Hospital of Geneva, Switzerland.
Lew
D
D
Hirschel
B
B
Auckenthaler
R
R
Morabia
A
A
Heald
A
A
Benedict
P
P
Terrier
F
F
Wunderli
W
W
Matter
L
L
Germann
D
D
Voegeli
J
J
Stalder
H
H
D000328:Adult; D000658:Amoxicillin / Q000627:therapeutic use; D019980:Amoxicillin-Potassium Clavulanate Combination; D001424:Bacterial Infections / Q000188:drug therapy*; D002969:Clavulanic Acids / Q000627:therapeutic use; D003139:Common Cold / Q000188:drug therapy* / Q000382:microbiology*; D004311:Double-Blind Method; D004359:Drug Therapy, Combination / Q000627:therapeutic use*; D005260:Female; D006192:Haemophilus Infections / Q000188:drug therapy; D006193:Haemophilus influenzae / Q000302:isolation & purification; D006801:Humans; D008297:Male; D001936:Moraxella catarrhalis / Q000302:isolation & purification; D009305:Nasopharynx / Q000382:microbiology*; D016870:Neisseriaceae Infections / Q000188:drug therapy; D011008:Pneumococcal Infections / Q000188:drug therapy; D016896:Treatment Outcome
D002969:Clavulanic Acids; D019980:Amoxicillin-Potassium Clavulanate Combination; D000658:Amoxicillin