Is Verapamil a Better Magnesium Agonist Rather Than a Calcium Antagonist? A Hypothesis?

Mg and verapamil have similar effects on the cardiovascular system. Both the agents have been successfully used for the treatment of hypertension and protection of the ischaemic myocardium. The exact mechanism of action of calcium blocking drugs including verapamil is unknown. It is proposed that verapamil stimulates the Mg-carrying transport system and Mg diffusion in the cell so that Mg influx is enhanced. This in turn causes suppression of the slow inward Ca current and fast inward Na current resulting into decreased transport of Ca and Na. Verapamil possibly also influences outward K and Mg currents and alter the shape and duration of the action potential. Since Mg ions maintain the structural and functional integrity of the cardiovascular system, therefore Mg mediated mechanisms of action for verapamil appears to be more logical.