Dopamine is a neurotransmitter (which means it is used to help nerves throughout the brain and the body communicate). One of the effects dopamine has in the blood is to cause the heart to beat faster and harder. Thus dopamine can be administered intravenously to patients who are having heart problems (including cardiac arrest) or have low blood volume (including that caused by kidney failure).
Cardiovascular Risks
Because dopamine primarily works on the heart and the cardiovascular system, most of the dangers associated with its use have to do with the heart. Intravenous (IV) dopamine can cause a variety of heart problems, including bradycardia (slow heart rate), ventricular tachycardia (rapid heartbeat originating from the heart's ventricles), ectopic beats (unusual or mis-timed heartbeats) and widened QRS complexes (an EKG finding that suggests unusual electrical activity in the heart), as well as heart pain, heart palpitations and irregular heartbeat. IV dopamine can also cause rapid fluctuations in blood pressure, including hypotension (low blood pressure) and hypertension (high blood pressure).
Other Risks
Use of IV dopamine can also affect other organs throughout the body. In the gastrointestinal system, it can lead to nausea and vomiting. IV dopamine can also affect the respiratory system by causing dyspnea (slowed breathing). Its effects on the nervous system include nervousness and anxiety. IV dopamine can also cause dermatological piloerection (the sensation that the hairs on the skin are standing up). It may lead to development of gangrene in some patients, particularly those who are receiving high doses or those who already have problems with vascular disease.
Other Dangers
IV dopamine can interact with certain medications, especially a class of medications called monoamine oxidase inhibitors. Because these drugs work to help inhibit the breakdown of dopamine, patients who receive IV dopamine and are also taking these drugs may develop dangerously high dopamine levels. IV dopamine may also increase the effects of diuretics and a class of antidepressants called tricyclic antidepressants. The effects of IV dopamine are hindered by beta blockers. Also, because some formulations of IV dopamine are mixed with dextrose, they should not be combined with any IV fluids that contain blood, as this can cause the blood to break down in the bag or to begin to clot. IV dopamine is safe for administration to blood flowing in the veins, however, because it becomes diluted so quickly.
