Evidence that Parkinson’s drug levodopa may cause freezing of gait should be addressed with new studies that investigate a possible shift to alternative dosing strategies or treatment options. That’s according to a new editorial by European scientists, published this week in JAMA Neurology.

Levodopa generally reduces freezing of gait, in which patients’ attempts to take steps are ineffective. But two recent studies have shown that untreated patients with Parkinsonism did not show freezing of gait, even when their condition was severe, write Jorik Nonnekes, M.D., Ph.D., of Radboud University Medical Centre, the Netherlands, and colleagues.

Other recent observations suggest that freezing of gait was rare before Parkinson’s patients were routinely treated with levodopa, they add. With these findings in mind, it’s difficult to reconcile levodopa’s benefits with the possibility that the drug, or the way in which it is administered, may be causing the problem, write the authors. 

Nonnekes and colleagues recommend that future research compare outcomes in patients who start levodopa early in the disease’s progression with the outcomes of those who delay treatment. Studies could also investigate the effects of administering levodopa more continuously from treatment outset using controlled-release preparations, they said. Alternative treatments such as deep-brain stimulation should receive added attention as well, they concluded.

Levodopa is the most common first-line treatment prescribed to manage Parkinson’s disease symptoms, according to the Parkinson’s Foundation.