However, the study insists that they do reduce the risk of pneumonia after chest infection, especially in elderly people.
"On the basis of the evidence in this study, there seems to be a substantial gap between evidence based guidance and general practitioners' prescribing behaviour," the British medical Journal quoted the authors, as saying.
Risk of serious complications in the month after analysis was recorded: mastoiditis (infection of the mastoid bone of the skull) after ear infection, quinsy (an abscess at the back of the throat) after sore throat, and pneumonia after upper respiratory tract infection and chest infection.
The number of patients for treatment to put off one complication was also recorded.
Only in rare cases, there are serious complications after upper respiratory tract infections, sore throat, and ear infection. Though antibiotics reduced the risk, over 4,000 courses were required to prevent one complication.
However, the risk of pneumonia following chest infection was quite high, particularly in elderly people, and was significantly reduced by antibiotic use.
The authors conclude that general practitioners should not base their prescribing for sore throat, ear infection, or upper respiratory tract infections, expecting serious complications.
However, antibiotic prescribing to reduce the risk of pneumonia after chest infection is justifiable, particularly in elderly patients in whom the risk is highest.