(1) Nitrates: e.g., glyceryl trinitrate, isosorbide dinitrate/mononitrate
These dilate both arteries and veins, and are the longest established
drugs for the treatment of angina.
(2) Calcium antagonists: e.g., nifedipine, verapamil, diltiazem
These drugs interfere with the movement of calcium into muscle cells,
so reducing the strength of contraction both of the muscle found in blood
vessel walls and heart muscle (but not of the muscles in the arms and legs,
which work in a different way). Reducing the force of contraction of the
heart can reduce energy needs and so help in preventing angina.
Calcium antagonists also affect the electrical properties of some heart
cells and have proved useful in the prevention or treatment of irregularities
of the heart-beat.