PD output parameters in a PK/PD model

The output parameters for PD models in a linked PK/PD model differ from the parameters for PD models that are not linked. The following list shows the PD model parameters used in linked PK/PD models.

101 Simple Emax model

Estimated parameters: Emax, EC₅₀, Ke0

102 Simple Emax model with a baseline effect

Estimated parameters: Emax, EC_50,E0, Ke0
Secondary parameters: Rmax, F_Emax

103 Inhibitory effect E0 model

Estimated parameters: E0, IC₅₀, Ke0

104 Inhibitory effect Imax model with a baseline effect

Estimated parameters: Imax, IC₅₀, E0, Ke0
Secondary parameters: Rmax, F_Emax

105 Sigmoid Emax model

Estimated parameters: Emax, EC₅₀, Gamma, Ke0

106 Sigmoid Emax model with a baseline effect

Estimated parameters: Emax, EC_e50, E0, Gamma, Ke0
Secondary parameters: Rmax, F_Emax

107 Inhibitory effect sigmoid E0 model

Estimated parameters: E0, IC₅₀, Gamma, Ke0

108 Inhibitory effect sigmoid Imax model with a baseline effect

Estimated parameters: Imax, IC₅₀, E0, Gamma, Ke0
Secondary parameters: Rmax, F_Emax

Below are definitions for the estimated and secondary parameters.

Emax: Maximum drug effect.

Imax: Maximum drug inhibition.

EC₅₀: Concentration in plasma that achieves 50% of predicted maximum effect in an Emax model.

ECe₅₀: For effect compartment models, the concentration at the effect site that achieves 50% of predicted maximum effect in an Emax model.

IC₅₀: Drug concentration required to produce 50% of the maximal inhibition.

E₀: Baseline effect (effect at 0). In models 103 and 107, E0 could also be named Imax, the maximum drug inhibition.

Gamma: Shape parameter.

Ke0: Exit rate constant from effect compartment.

Rmax: Observed or predicted maximum response.

F_Emax: Fractional change in response from baseline E₀.