Antibiotics are not justified to reduce the risk of complications after respiratory tract infection, sore throat or ear infection, a study has shown.
However they do reduce the risk of pneumonia after chest infection, particularly in older people.
Researchers identified 3.36m cases of respiratory tract infection recorded between 1991 and 2001 in the UK General Practice Research Database.
They then determined whether complications were less common in people who were prescribed antibiotics compared with those who were not.
Findings showed 4,000 antibiotic courses were needed to prevent one complication after respiratory tract infection.
However the number of courses needed to treat one case of pneumonia was 39 for those aged over 65 and between 96 and 119 in younger age groups.