Amoxycillin and co-trimoxazole in presumed viral respiratory infections of childhood: placebo-controlled trial.

A double-blind randomized controlled trial of amoxycillin, co-trimoxazole, and placebo was conducted on 197 children presenting with presumed viral respiratory infections. Routine throat swabs were taken to exclude streptococcal diseases. The three disease categories studied--nasopharyngitis, pharyngotonsillitis, and bronchitis (including laryngotracheobronchitis)--showed a generally similar pattern of resolution irrespective of treatment. Nevertheless, seven out of 66 children receiving placebo were withdrawn from the trial with unremitting symptoms or complications thought to require antimicrobial treatment. Only two of 56 children receiving amoxycillin and none of 75 receiving co-trimoxazole were withdrawn. Three other children receiving amoxycillin and three receiving placebo were seen during the trial but further treatment was not thought to be necessary. Thus the return consultation rate in children receiving placebo therapy was 15% compared with 4% for those receiving antimicrobial treatment. Antimicrobial treatment was associated with less nasal discharge on the eighth day of treatment. Placebo treatment allowed an earlier return to normal activity. There was a high incidence of possible side effects on all regimens including placebo. It is concluded that the benefits of antimicrobial treatment in presumed viral respiratory infections are marginal, and they should not be routinely prescribed for these conditions.