(January 15, 2010 - Insidermedicine)

Antibiotics and other drugs used to fight infections should be individually dosed based on patients' physical characteristics in order to maximize the drugs' effectiveness and safety, according to a Viewpoint argument made in the The Lancet.

Here is some information about antimicrobial drugs:

•    They are drugs used to kill germs, including bacteria and fungi, which can cause disease

•    Some microbes are developing resistance to antimicrobial drugs

•    Taking antimicrobial drugs only as prescribed by a health care professional can help diminish the threat of resistance

Researchers from the Alfa Institute of Biomedical Sciences in Athens provided many compelling reasons why antimicrobial drugs should be dosed based on patients' individuals characteristics instead of using the same dose for all adults. In the face of globalization and the worldwide epidemic of obesity, physicians today are likely to treat adults who vary dramatically in size and body composition from one another. At the same time, there is good evidence that the way antimicrobial drugs are broken down and cleared by the body can be heavily influenced by such characteristics as body size and the proportion of fat to lean body mass present. In addition, as the threat of drug-resistant germs increases, it is crucial that currently available antimicrobial drugs be used in a matter than maximizes their effectiveness.

An unresolved issue is exactly what body characteristics to take into account when determining the appropriate dose of an antimicrobial drug. Body weight, amount of lean body mass, amount of fat, and body surface area can all affect how a drug performs. It remains unclear which of these physical characteristics dosing adjustments should be based on.

We spoke with Dr Matthew E Falagas, one of the author's of the viewpoint, who offered some further insight.

Today's research suggests there is a need to move away from a "one size fits all" approach to dosing antimicrobial drugs and instead tailor the dose to the individual. Always follow your physicians' instructions carefully when taking antibiotics and other antimicrobial drugs.