Fig. 2

CYP2C19 status of the liver and its influence on drug metabolisation. The cytochrome P450 system of the liver is essential for the metabolisation of drugs in the body. CYP2C19 poor metabolisers show higher drug concentrations and adverse events. In contrast, in rapid/fast metabolising individuals, drug concentrations tend to be lower, leading to fewer adverse events, but therapy failure is also much more common