Therapeutic effect of an inhaled levodopa dry powder formulation on off episodes in patients with Parkinson's disease.

Background: Limited treatment options with a rapid onset of action are available to treat off episodes in Parkinson's disease (PD) patients. Therefore, the development of rapid onset formulations, for instance with levodopa, is warranted, which was the reason to investigate an inhalable formulation of levodopa.

Objectives: The primary objective was to determine the duration until maximum effect is reached of inhaled levodopa on the improvement of motor function of PD patients.