Traditional, low-dose courses of antibiotics that last for 10 to 14 days are less effective than higher-dose, shorter courses and allow bacterial resistance to emerge, Dr Glen Tillotson (research fellow, Royal Free hospital, London) said at a Global Challenges in the Management of Respiratory Tract Infections meeting held in Cologne, Germany recently. He added that current attitudes to antibiotic prescribing dated from times when higher doses of older antibiotics increased side effects such as diarrhoea.