add_indirect_effect#
- pharmpy.modeling.add_indirect_effect(model, expr, prod=True)[source]#
Add indirect (turnover) effect
The concentration \(C_c\) has an impact on the production or degradation rate of the response R:
Production:
\[\frac {dR}{dt} = k_{in} \cdot (1 + f(C_c)) - k_{out} \cdot R\]Degradation:
\[\frac {dR}{dt} = k_{in} - k_{out} \cdot (1 + f(C_c)) \cdot R\]
\(k_{in}\) and \(k_{out}\) can either be inhibited or stimulated. Baseline \(B = R(0) = R_0 = k_{in}/k_{out}\).
Models:
Linear:
\[f(C_c) = \text{slope} \cdot C_c\]Emax:
\[f(C_c) = \frac {E_{max} \cdot C_c } { EC_{50} + C_c }\]Sigmoidal:
\[f(C_c) = \frac{E_{max} \cdot C_c^n}{EC_{50}^n+C^n}\]
- Parameters:
model (Model) – Pharmpy model
prod (bool) – Production (True) (default) or degradation (False)
expr ({‘linear’, ‘emax’, ‘sigmoid’, ‘step’}) – Name of PD effect function.
- Returns:
Model – Pharmpy model object
Examples
>>> from pharmpy.modeling import * >>> model = load_example_model("pheno") >>> model = add_indirect_effect(model, expr='linear', prod=True)