Common colds: What happens if you wait before trying start antibiotics?

Antibiotics are not going to help most children with simple colds, and will only help with middle ear infections a bit. This needs to be balanced against the adverse effects, and waiting a day to start the antibiotics might mean they are no longer needed.

The belief in antibiotics goes deep. These medicines are often used for children and adults for simple colds, sore throats and middle ear infections, even though they cannot usually help very much. This is because these conditions are usually caused by viruses, and the body usually gets them under control without help within a week. Antibiotics don't work against viruses - they are only effective against bacteria.

Even though it is widely known that antibiotics do not help much with colds, a lot of patients still leave the doctor's surgery with a prescription for antibiotics when they have a cold. It is not only that this might be a waste: antibiotics also have adverse effects such as diarrhoea, nausea, rashes and vaginal thrush.

Researchers therefore have looked at ways to reduce the unnecessary use of antibiotics, without denying people the medications they might need. One idea is this: to get a prescription for antibiotics, but with the advice not to use it straight away. Waiting for a day or two might mean that the infection gets better by itself. If not, and the person gets sicker or is not getting better, then they can still start using the antibiotics.

To see whether this strategy works, researchers from the Cochrane Collaboration studied the available trials. They found seven trials altogether in which the patients - mostly children - were divided into two groups. In one group, the patients were advised to take the antibiotics straight away. The other group was advised to start taking them 48 hours later.

The results showed that there was not a lot of benefit from taking the antibiotics straight away. For children who had sore throats or middle ear infections pain and fever went away a bit more quickly. For coughs and colds, though, there was not a lot of benefit in taking the antibiotics early. About half of the children who waited did not need to use the antibiotics at all when the 48 hours were up. That meant that they avoided the risk of adverse effects.

© IQWiG (Institute for Quality and Efficiency in Health Care)