UK51656 is a calcium antagonist with IC50 of 4 nM.
UK51656 has an elimination half-life of 4.7 h, which is consistent with its duration of action in the anesthetized dog. The effect of UK51656 on coronary vascular resistance, has markedly long durations, being over 5 h[1].
[1]. Alker D, et al. Long-acting dihydropyridine calcium antagonists. 4. Synthesis and structure-activity relationships for a series of basic and nonbasic derivatives of 2-[(2-aminoethoxy)methyl]-1,4-dihydropyridine calcium antagonists. J Med Chem. 1990 Feb;33(2):585-91.