What is the onset time for fospropofol?

What is the onset time for fospropofol?

• A. 1-2 minutes
• B. 20-30 seconds
• C. 5-13 minutes
• D. 30-60 minutes

Answer: (C)

Fospropofol is a water-soluble prodrug of propofol. It must be cleaved by alkaline phosphatase to become active propofol, so the sedative effect appears after this metabolic conversion. That extra step slows the onset compared with propofol itself, which acts immediately. Clinically, the time to achieve adequate sedation with fospropofol is typically in the range of about 5 to 13 minutes, depending on dose and patient factors. The much faster onsets (seconds to a couple of minutes) describe direct propofol, while much longer times (tens of minutes to an hour) don’t fit the drug’s pharmacodynamics.

Fospropofol is a water-soluble prodrug of propofol. It must be cleaved by alkaline phosphatase to become active propofol, so the sedative effect appears after this metabolic conversion. That extra step slows the onset compared with propofol itself, which acts immediately. Clinically, the time to achieve adequate sedation with fospropofol is typically in the range of about 5 to 13 minutes, depending on dose and patient factors. The much faster onsets (seconds to a couple of minutes) describe direct propofol, while much longer times (tens of minutes to an hour) don’t fit the drug’s pharmacodynamics.