The FDA is investigating the possibility that pramipexole (Mirapex) increases the risk for heart failure.

In a pooled analysis of randomized trials, the drug — used to treat Parkinson disease and restless legs syndrome — showed an increased incidence of heart failure relative to placebo, but the results weren’t statistically significant. Further review of two epidemiologic studies also found an increased risk, but confounding factors may have influenced the results, according to the FDA.

Until the agency completes its review, it is instructing clinicians to continue prescribing pramipexole according to the recommendations on the label. Patients should be counseled about the potential risk.

Source: FDA MedWatch safety alert.