Twenty-one studies were included: 8 double-blind trials (n=126), six of which were of a crossover design, and 13 uncontrolled open-label studies (n=202).
Following administration of apomorphine, the decrease in daily 'off' time from baseline ranged from 2.6 to 4 hours (6 studies) and 20.5% and 22% (2 studies) of the waking day in the open-label studies. Two studies reported that the difference was statistically significant, while six did not report a statistical comparison. The mean delay of onset ranged from 6 to 14 minutes (6 studies). The mean duration of effect ranged from 36 to 61.9 minutes (5 studies).
In the double-blind trials, all of the studies except one reported a statistically significant difference between apomorphine and placebo (8 studies) or levodopa (1 study) for motor functioning, with the improvement in favour of apomorphine. The mean delay of onset ranged from 8.1 to 22 minutes (3 studies). The mean duration of effect ranged from 56.6 to 96 minutes (2 studies).
Based on one study of 29 participants, which the authors stated provided the most extensive data on adverse events in apomorphine-naive patients, several adverse events were reported. The most common adverse events (30% or greater) were injection-site reaction, yawning, dyskinesias, drowsiness and nausea or vomiting.