Principles of antibiotic pharmacodynamics include factors that are importan
t for effective eradication of bacteria as well as the suppression of resis
tance. For effective eradication of bacteria and a good clinical outcome, a
ratio for the area under the plasma concentration-time curve relative to t
he minimum inhibitory concentration (AUC/MIC) of greater than 100 is needed
for gram-negative organisms, and a level of greater than 30 is required fo
r gram-positive organisms. Pharmacodynamic principles can also be used to d
evise the optimal administration regimen for specific antimicrobial agents.
Pharmacodynamic analysis of the activity of levofloxacin against Streptoco
ccus pneumoniae revealed that, 99% of the time, actual hospitalized patient
s achieve an AUC/MIC of greater than 30. This indicates that levofloxacin w
ill be very effective in treating S. pneumoniae infections in the majority
of patients. Cost of treatment is an increasing concern voiced by healthcar
e providers and users alike. This has led to a much greater emphasis placed
upon the cost of individual drug used in the management of infections. How
ever, when evaluating the cost of an antibiotic, it is extremely important
that not only are the direct acquisition costs assessed, but consideration
also given to other aspects incurring a financial burden, such as drug prep
aration cost, supplies, costs of treating adverse events or any treatment f
ailures. It is only by having such a full assessment of costs that realisti
c financial comparisons can be made between different antibiotics. Copyrigh
t (C) 2000 S. Karger AG, Basel.