General responses to selected questions from Joel Braunstein, MD, of Johns Hopkins University and Joseph Toscano, MD.
Question:
I have just read an article indicating that pergolide – which is used to treat Parkinson's Disease and restless leg syndrome – has been linked to heart valve disease. I have been on mirapex – which stimulates serotonin receptors to treat Parkinson's and restless legs – for 7 years and have recently had an acute cardiac event resulting in two stints. Could mirapex be a factor in my heart disease? I have no other risk factors.
Answer:
You are right about a possible link between pergolide and valvular heart disease. This was reported in 3 patients in the medical literature in December 2002. There have been no similar reports regarding mirapex that I can find. Pergolide and mirapex differ chemically, though both have a similar action at the level of the brain, stimulating dopamine receptors to help control movement disorders like Parkinson's and restless leg syndrome. It is uncertain exactly how either affects the heart, if at all, and exactly how pergolide would damage heart valves, though valve specimens from those 3 patients apparently showed similar thickening of the coating of the valves.
It sounds like your acute cardiac event was related to coronary artery disease (CAD) due to blockages within the heart's own blood vessels. This would have an entirely different cause than valvular heart disease, so the above information is not helpful in figuring out any relationship between the medication and your event. I can find no reports of a causal connection between these medications and CAD, though both myocardial infarction (heart attack) and angina pectoris (chest pain related to CAD) are listed in a section describing (rare) adverse events experienced by patients while taking mirapex in that product's package insert. (This is somewhat of a disclaimer on the manufacturer's part.) Unfortunately, most patients taking the medication tend to be older and otherwise at risk for these events. Because so few occurred, there is no way to know for sure whether the mirapex actually increased the risk; it would require a long-term, organized study with tens of thousands of patients to be certain, and it is unlikely that this will be performed.
