Developments in PK/PD: optimising efficacy and prevention of resistance. A critical review of PK/PD in in vitro models.

In vitro pharmacokinetic models are excellent tools with which to study an antibacterial's pharmacodynamics (pD), being flexible, adaptable, low cost, and correlating well with animal and human systems. They can be used to perform simple descriptive studies on antibacterial effect, determine the dominant pD factor and its magnitude for antibacterial effect, and finally be used to assess the effect of dosing on emergence of resistance. A wide range of model designs are used and some standardisation maybe of value in the near future, however it is clear that in vitro models in conjunction with animal studies and human trials offer an excellent way of studying drug dosing to optimise outcomes.