Mibefradil dihydrochloride hydrate, a potent T-type calcium antagonist, belongs to a new class of Ca²⁺ antagonists, the tetralol derivatives. It selectively blocks T-type Ca²⁺ channels in contrast to other Ca²⁺ antagonists which block only L-type channels¹. Mibefradil also modulates the gating properties of K_V10.1 channel⁶. It also blocks Orai1-3 channels with the following IC₅₀: 52.6, 14.1, and 3.8 μM respectively, in whole-cell and excised-membrane patch clamp⁷.

Mibefradil dihydrochloride hydrate has moderate selectivity for T-type Ca²⁺ channels displaying IC₅₀ values of 2.7 μM and 18.6 μM for T-type and L-type channels respectively². Mibefradil relaxes coronary arteries without suppressing myocardial contractility and causes a dose-related decrease in heart rate. Mibefradil demonstrated end organ protection such as preventing neointima formation after vascular injury and myocardial hypertrophy³. In addition, it has been shown that it inhibits human cancer cell proliferation in vitro with several cell lines including glioblastoma (GB), by inhibiting passage beyond the G1/S interphase^4,5.