Zamicastat (BIA 5-1058) is a dopamine β-hydroxylase (DBH) inhibitor and can cross the blood-brain barrier (BBB) to cause central as well as peripheral effects. Zamicastat is also a concentration-dependent dual P-gp and BCRP inhibitor with IC 50 values of 73.8?μM and 17.0?μM, respectively. Zamicastat reduces high blood pressure.