# Pharmacodynamics

## Linear vs. Log Graphs

As concentration increases, effect approaches a maximum, e.g. a blood vessel cannot dilate forever or it will explode!

The maximum effect is called the Emax. The concentration at which the effect is 50% of the maximum is called the EC50.

The shape of the linear graph is called a rectangular hyperbola. The shape of the log graph is called a sigmoid curve.

Toggle the grey button to see the different graphs.

Effect (%)

Concentration