Overuse of antibiotics spurs vicious cycle

June 23, 2010

Patients whose doctors over-prescribe antibiotics may develop drug resistance that can last up to a year, putting them and others at risk when more serious treatment is needed, according to a study published in May in the British Medical Journal.

Patients whose doctors over-prescribe antibiotics may develop drug resistance that can last up to a year, putting them and others at risk when more serious treatment is needed, according to a study published in May in the British Medical Journal.

The more antibiotics that are prescribed for coughs, flulike illnesses, or urine infections, the more bacteria become resistant in a vicious cycle, said British researchers who analyzed 24 previous studies of antibiotic resistance.

“The effect is greatest in the month immediately after treatment, but may last for up to a year, and this residual effect may be a driver for high levels of resistance in the community,” said Alastair Hay, research leader and a consultant senior lecturer in primary healthcare at Bristol University in England.

Medical experts believe the overuse of antibiotics in the United States, Europe, and other wealthy regions is building widespread resistance, threatening vital medical treatments from a number of therapies. Antibiotics are needed to prevent bacterial infection. But antibiotics can be rendered useless if they are used so frequently that bacteria develop ways to outwit them. Hay said his study showed how individual resistance was building up and how that translated into community- or population-wide problems.

Multi-drug-resistant bacteria are a growing problem in hospitals worldwide, marked by the rise of “super bug” infections like methicillin-resistant Staphylococcus aureus.

But Hay said the problem of antibiotic resistance is often ignored by doctors, despite the fact that approximately 80% of antibiotic prescriptions come from family physicians.

“Up until now, the majority of the evidence has been at a population level, so it was very easy, both for clinicians and patients, to say ‘this isn’t my problem’ or ‘just one more antibiotic isn’t going to make a difference,’” Hay said. “But the more we prescribe, the more the bacteria become resistant. And really the only way of turning that vicious cycle into a virtuous circle is to only prescribe when it is absolutely necessary.”

Experts say the annual cost in the United States of treating infections traceable to just six drug-resistant bacteria is more than $1.87 billion, more than the yearly cost of treating the flu. In the European Union, added costs and loss of productivity as a result of antibiotic resistance are estimated at approximately 1.5 billion euros ($1.85 billion) a year.

In a commentary, Chantal Morel and Elias Mossialos, specialists in economics and health policy at the London School of Economics, said the study showed the need for new classes of antibiotics to be developed. They said financial incentives should be used to persuade drug companies to invest in research to find, test, and develop new antibiotics.

“In view of the rapid growth of antibiotic resistance ... the intricacies of the antibiotics market, and the cost savings from improved treatment, there is a public health [and] economic justification for intervention,” Morel and Mossialos wrote.