(±)-Verapamil-d
3 (hydrochloride) is intended for use as an internal standard for the quantification of verapamil by GC- or LC-MS. Verapamil is the prototypical blocker of L-
type calcium channels that produces excitation-
contraction uncoupling in cardiac muscle by preventing the slow-
inward current of calcium ions.
1 Verapamil can also block calcium fluxes in vascular smooth muscle. It has both peripheral and coronary vasodilator effects (IC
50 = 0.38 μM in guinea pig aortic strip) and has been used to control hypertension, angina, cardiac arrhythmia, and vascular headaches.
2,3,4 Verapamil has also been used in cell biology as an inhibitor of drug efflux pump proteins such as P-
glycoprotein, which are often over-
expressed in certain tumor cell lines.
5
1. Singh, B.N. The mechanism of action of calcium antagonists relative to their clinical applications Br. J. Clin. Pharmacol. 21(Suppl 2),109S-121S(1986).
2. Dei, S., Romanelli, M.N., Scapecchi, S., et al. Verapamil analogues with restricted molecular flexibility: Synthesis and pharmacological evaluation of the four isomers of α-[1-[3-[N-[1-[2-(3,4-dimethoxy-phenyl)ethyl]]-N-methylamino]cyclohexyl]]-α-isopropyl-3,4-dimethoxybenzene-acetonitrile J. Med. Chem. 36(4),439-445(1993).
3. Dawson, J.R., Whitaker, N.H., and Sutton, G.C. Calcium antagonist drugs in chronic stable angina. Comparison of verapamil and nifedipine Br. Heart J. 46(5),508-512(2013).
4. Campbell, T.J., and Williams, K.M. Therapeutic drug monitoring: Antiarrhythmic drugs Br. J. Clin. Pharmacol. 46(4),307-319(1998).
5. Rabindran, S.K., He, H., Singh, M., et al. Reversal of a novel multidrug resistance mechanism in human colon carcinoma cells by fumitremorgin C Cancer Res. 58(24),5850-5858(1998).
