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Size a factor in antibiotics dosage


The “one-size fits all” approach to prescribing antibiotics is no longer effective and larger patients may need to be given higher doses, according to doctors.

Infections in larger adults, including those who are obese, may not clear with the standard doses and doctors have argued that it increases the risk of developing resistance.

Work needs to be done on guiding GPs on when it is appropriate to alter doses, said an editorial in the Lancet, which supplemented a study by doctors in the US and Greece. However, GPs said the theory was interesting but could prove to be expensive.

The concentration of antibiotics in a body can be effected by the size and proportion of body fat a person has, meaning the effect could be reduced in larger patients, the study said. If a dosage is too small to clear an infection, then the resistance may be increased and cause further problems for doctors.

Chair of the Royal College of GPs, Professor Steve Field, said many patients were given antibiotics unnecessarily and he would encourage “appropriate” prescribing.

Copyright Press Association 2010

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