Vasodilator therapy has become a major pharmacologic approach for improving left ventricular function, and consequently,
vasodilator drugs are being used increasingly in the treatment of
heart failure. Ideally,
vasodilator drugs used in the long-term management of
heart failure should show clearly defined pharmacodynamic effects. These include reduced impedance to left ventricular ejection, increased venous capacitance, increased left ventricular ejection fraction and reduced heart size, absence of neurohormonal stimulation, and slowed progression of
left ventricular dysfunction. The mechanisms of action and sites of activity of the various
vasodilator drugs currently available vary considerably, and none as yet has proved ideal for the treatment of
heart failure or
hypertension. The complexity surrounding the multiple
vasoconstrictor mechanisms involved in
heart failure has led to a rationale for combined
vasodilator therapy and certain combinations are discussed. From a therapeutic standpoint, the development of drugs with multiple mechanisms of action is particularly attractive.
Flosequinan is a new
vasodilator agent whose cellular mechanism of action remains uncertain.
Flosequinan has the advantage of being able to relax both arterial and venous beds and as such may be particularly beneficial in the treatment of
heart failure.