Pramipexole, the dopamine agonist approved for treating Parkinson’s disease and restless legs syndrome, may be associated with an increased risk for heart failure, according to a statement issued by the Food and Drug Administration.
"Results of recent studies suggest a potential risk of heart failure that needs further review of available data," but the FDA has not concluded that the drug increases the risk of heart failure, the FDA said in the Sept. 19 statement.
The FDA is currently working with Boehringer Ingelheim, which markets pramipexole as Mirapex, to investigate this association further and will provide an update when more information is available.
The studies include a pooled analysis of randomized clinical trials, which found more cases of heart failure (12 of 4,157 patients) among patients treated with pramipexole than among those on placebo (4 of 2,820). The difference between groups, however, was not statistically significant.
In two epidemiologic studies using European data, though, the increased risk of heart failure associated with pramipexole was statistically significant. In one of the studies, a case control study using a database of patients aged 40-89 years treated with anti-parkinsonian drugs, the risk of heart failure associated with any use of a dopamine agonist compared with no use was increased by almost 60% (relative risk, 1.58). The heart failure risk associated with use of pramipexole (RR, 1.86) and with another dopamine agonist, cabergoline (RR, 2.07), were each higher compared with no use of these drugs.
In the other epidemiologic study, current use of pramipexole was associated with an increased risk of heart failure, compared with levodopa. The risk was increased in the first 3 months of treatment and among patients aged 80 years and older, but was no higher among people who had been treated with pramipexole for more than 3 months.
This last finding is "difficult to explain," since heart failure is a chronic condition, and the studies had limitations, which "make it difficult to determine whether excess heart failure was related to Mirapex use or other influencing factors," the FDA statement said.
The agency advises that health care professionals continue following recommendations in the pramipexole label and that patients continue to take the medication as directed.
Pramipexole was approved in July 1997.
The full FDA notice is available here. Serious adverse events associated with pramipexole should be reported to the FDA’s MedWatch program by clicking here or by calling 800-332-1088.