Delays in ON Time Common Among Levodopa-Treated Patients

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The most frequently reported symptoms while patients waited for ON-period included slowness, fatigue, reduced dexterity, difficulty in walking, and problems with balance.

Data derived from routine clinical practice indicate that delays in ON time are common among levodopa-treated patients with Parkinson disease (PD) who experience motor fluctuations, and are a major contributor to early morning OFF periods, according to the results of a single-visit pilot study. Findings from the study were published in the European Journal of Neurology.

During a single visit, adult patients with idiopathic PD who were attending a routine appointment and had been receiving levodopa for ≥1 year completed a Time-to-ON Questionnaire, in which they evaluated the time to ON-period and the symptoms they experienced while waiting. Following this, patients then completed a 5-day home time-to-ON diary, in which they recorded the time involved to ON after receiving their first morning levodopa dose in 5-minute increments.

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A total of 151 participants completed the study survey, of whom 64.2% (97 of 151) experienced motor fluctuations. Among the patients who experienced motor fluctuations, 56% (54 of 97) reported delays in ON time (ie, latency >30 minutes) after taking their first morning dose of levodopa. Moreover, 51% of participants reported that they had experienced delayed ON ≥1 time in the previous week, with 21% indicating that they had experienced delayed ON time during all 7 mornings of the previous week.

Furthermore, 10% of the participants reported having experienced dose failures on ≥4 mornings during the prior week. The most frequently reported symptoms while patients waited for ON-period included slowness (94.8%), fatigue (87.6%), reduced dexterity (82.5%), difficulty in walking (66.0%), and problems with balance (59.8%).

The researchers concluded that early morning OFF difficulties among levodopa-treated patients with PD, including delays in time to ON, are quite common. The Time-to-ON Questionnaire may prove to be a valuable and practical tool to use in the clinic for exploring problems with time to ON-period.


Stocchi F, Coletti C, Bonassi S, Radicati FG, Vacca L. Early morning OFF and levodopa dose failures in patients with Parkinson’s disease attending a routine clinical appointment using Time-to-ON Questionnaire [published online December 26, 2018]. Eur J Neurol. doi: 10.1111/ene.13895