Amlodipine-d₄is intended for use as an internal standard for the quantification of amlodipine by GC- or LC-MS. Amlodipine is a dihydropyridine L-type calcium channel blocker that selectively inhibits calcium influx in cardiac and vascular smooth muscle.¹Acting as a vasodilator, amlodipine reduces blood pressure by relaxing the smooth muscle in the arterial wall, decreasing total peripheral resistance. It inhibits calcium-induced contractions in depolarized rat aorta with an IC₅₀value of 1.9 nM, displaying a slow rate of association and dissociation in isolated vascular and cardiac tissues.¹Amlodipine also demonstrates actions independent of L-type calcium channel blockade by regulating membrane fluidity and cholesterol deposition, stimulating nitric oxide production, acting as an antioxidant, and regulating matrix depositionin vitroandin vivo.²Formulations containing amlodipine have been used in the treatment of hypertension.

1.Burges, R.A., Gardiner, D.G., Gwilt, M., et al.Calcium channel blocking properties of amlodipine in vascular smooth muscle and cardiac muscle in vitro: Evidence for voltage modulation of vascular dihydropyridine receptorsJ. Cardiovasc. Pharmacol.9(1)110-119(1987) 2.Mason, R.P., Marche, P., and Hintze, T.H.Novel vascular biology of third-generation L-type calcium channel antagonists: Ancillary actions of amlodipineArterioscler. Thromb. Vasc. Biol.23(12)2155-2163(2003)