 Compared to other calcium channel blockers such as dihydropyridine derivatives, verapamil and diltiazem, flunarizine has low affinity to voltage-dependent calcium channels.It has been theorised that it may act not by inhibiting calcium entry into cells, but rather by an intracellular mechanism such as antagonising calmodulin, a calcium binding protein.Flunarizine is well absorbed (>80%) from the gut and reaches maximal blood plasma concentrations after two to four hours, with more than 99% of the substance bound to plasma proteins.