“We feel that’s not the optimal way go,?he said. “It doesn’t give you the full story ?it doesn’t tell you, for example, how quickly the bacteria are killed.?/p>
So UF scientists developed a system of pumps they can use to expose bacteria to changing concentrations of an antibiotic, mimicking the concentration profile present in a patient at the actual site of an infection. They then measure how quickly the bacteria are killed or see if they regrow, and use mathematical modeling to estimate the optimal dose.
“Based on the results in the lab, then you can do a clinical study of what you think is going to work best,?Derendorf said, “and you’d find the best dose much faster than just by going by trial and error or by using some of the traditional ways.?/p>
Consider one recent example: Derendorf led a series of laboratory experiments designed to evaluate an investigational, sustained-release form of a cephalosporin antibiotic. Ultimately the PK/PD approach showed that the difference in drug concentrations in the tissues arising from the standard form of the drug versus the sustained-release variety was so minimal, development of the new formulation was not warranted.
“The company that was interested in that decided not to continue that project any more and made that decision much sooner probably than they would have in earlier days,?said Derendorf, who published the findings in the Journal of Clinical Pharmacology. “Using the information early on to make a ‘no-go?decision for a product so you don’t do
Source:University Of Florida