What is the onset of action for apomorphine?

Apomorphine is a dopamine agonist that is primarily used in the treatment of Parkinson's disease, particularly to manage "off" episodes. The onset of action for apomorphine is characterized as quick, typically within minutes after administration. This rapid onset is crucial for patients with Parkinson's who may experience sudden fluctuations in their ability to move and control their symptoms.

When apomorphine is administered, it quickly stimulates the dopamine receptors in the brain, which helps alleviate the motor symptoms associated with these "off" periods. This quick action makes it effective for providing prompt relief and can be particularly beneficial for patients needing immediate intervention for motor control.

In contrast to the other options, a slow and gradual onset would not provide the necessary prompt relief expected during an "off" episode. A moderately quick or very slow onset also wouldn't align with the pharmacokinetics of apomorphine, which is designed for rapid action. Thus, the characterization of apomorphine’s onset as quick accurately reflects its pharmacological effectiveness in managing Parkinsonian symptoms swiftly.