Positive inotropic drugs improve heart function in cases of heart failure (when the heart is not pumping well enough), heart attacks and various types of heart disease. They can be divided into four types based on how they work:
Doctors very often prescribe one of the digitalis compounds, digoxin, for patients with heart failure. It increases the force of muscular contractions in the failing heart. Studies have shown that digoxin can improve the symptoms of heart failure in patients who are already taking diuretics (drugs that help rid the body of excess sodium salt and water) and ACE inhibitors, a type of vasodilator drug that helps widen blood vessels.
Apart from digoxin, other positive inotropic drugs should be used only for acute or end-stage heart failure because their prolonged use has been shown to worsen the disease outcome, and they may even increase the risk of death in some heart failure patients. These drugs can have a short-term benefit for some patients, but they may be harmful with long-term use.
Some positive inotropic drugs are given in pill form, and some are given intravenously (through a needle into a vein, usually in the arm). Patients who haven't responded to other treatments may be given intravenous positive inotropic drugs every so often on a regular basis. This is called intermittent therapy. It's a good idea for patients taking an intravenous positive inotropic drug to try stopping the drug every six months to see if they still need it.