This model assumes a linear relationship between the effect and the logarithm of the drug conc at the site of action over a certain range of drug concentrations.
It is important to remember that the log-linear relationship between the drug conc and effect, exists over a certain range of drug conc.
This relationship may not hold outside this range of conc. Linear regression can be performed between the effect and log drug conc to determine the slope. The slope is the pharmacodynamic model parameter which is a measure of the potency of the drug.
