Titrating cardiovascular drugs.

Titrating cardiovascular drugs is important to ensure efficacy and to minimize the risk of toxicity. A serum assay is extremely useful to guide digoxin therapy. Assessment of the effect of warfarin on blood clotting should be used to adjust dose. Serum cholesterol and lipid measurements guide therapy with antilipemic agents. The antihypertensive drugs, beta blockers, calcium channel blockers, and vasodilators can be assessed by their clinical effects. There is no strict relation between serum concentration of antiarrhythmic drugs and their effects, nor is it clear that the long-term efficacy of these drugs can be assessed by surrogate end points.