Fitergol Further information Nicergoline is an alpha-blocking cerebral vasodilator. The activity of nicergoline is primarily due to blockade of α 1 and α 2 adrenoceptors. Nicergoline also blocks serotonin and dopamine receptors. Nicergoline demonstrates a wide safety margin. Administration of up to 90 times the normal recommended dose in dogs for 6 months has shown no adverse effect.