Researchers in Belgium recently published their findings on a possible association between the use of pergolide (Permax®) and problems with the valves of the heart. (To see a review of the structure and function of the heart, please click here). Pergolide (a dopamine-receptor agonist) is a drug that mimics the effects of a chemical in the body that helps to regulate movement—dopamine—and  is approved by the US Food and Drug Administration for the treatment of Parkinson’s disease. It may also be used to treat restless legs syndrome. This drug is an ergot derivative, meaning that it has a chemical structure based on ergot, a substance that is produced from a fungus called Claviceps purpurea.
 
Several scientific papers have been published that have identified a possible increased risk of problems with heart valves with the use of pergolide; however, this is the first time that researchers have examined a large group of patients who are taking pergolide and determined the rate at which these problems occurred.
 
Dr. Van Camp and his associates used sound waves to create a moving picture of the heart (echocardiography) and examined the structures and pressures in the hearts of 96 people—78 of whom had taken pergolide for the treatment of Parkinson’s disease and 18 people who had Parkinson’s disease but who had never taken an ergot-derived dopamine-receptor agonist (these people served as the control group). Those who had taken pergolide were divided into two groups—a high-dose group (defined as those people taking 5 mg or more per day of pergolide) and a low-dose group (those taking less than 5 mg per day).
 
The researchers identified stiffening of the valves of the heart and regurgitation, or backward flow of blood through these valves, (restrictive valvular heart disease) in 42% of the patients in the high-dose group, 29% in the low-dose group, and 0% in the control group. Twenty patients had stiffening of the mitral valves, seven of the aortic valve, and six of the tricuspid valve. Those patients who had taken pergolide, as compared to those in the control group, had higher pressures in the blood vessels that carry the blood from the heart to the lungs (pulmonary hypertension).

Six patients stopped taking pergolide after they were found to have restrictive valvular heart disease; two of these six had less stiffening of their valves when they were reexamined six months later. However, the researchers noted that the size of the group that stopped taking pergolide was too small to be able to draw conclusions about the reversibility of the valvular disease.
 
The authors concluded, “Although pergolide remains a good treatment for the symptoms of Parkinson’s disease, our findings underline the necessity to inform patients of the possible risk of inducing restrictive valvular heart disease and pulmonary hypertension. Clinicians must be aware of this possible side-effect, and close clinical and echocardiographic follow-up is mandatory.”
 
Van Camp G, Flamez A, Cosyns B, et al. Treatment of Parkinson's disease with pergolide and relation to restrictive valvular heart disease. Lancet. 2004;363(9416):1179-1183.