:typing Fospropofol is a prodrug of propofol under development for sedation for a variety of procedures, including colonoscopy.[33, 34] Blood levels of propofol after administration of fospropofol reach lower peak levels and are more sustained than after administration of intravenous propofol (Figure 1). This effect creates ease of administration, because for short-duration endoscopic procedures, such as upper endoscopy or colonoscopy, patients may only require a single dose of fospropofol. To improve pain control and to facilitate targeting moderate sedation, fospropofol is co-administered with a narcotic, typically fentanyl. Fospropofol is associated with slight increases in serum phosphorus levels after intravenous administration, but no clinically significant adverse effects from increased phosphorus levels have been observed.[33, 34] Fospropofol administration can be accompanied by the development of paraesthesias during the initial administration, particularly in the groin area. Despite this, a preliminary report of a clinical trial indicates that patient satisfaction is very good.
A major potential advantage of fospropofol is that the drug manufacturer is seeking approval from the Food and Drug Administration for administration by non-anaesthesiologists. A successful application will avert a situation like that of propofol, for which the package insert suggests that administration should be performed by persons trained in general anaesthesia. http://www.medscape.com/viewarticle/537718_3
Following the administration of fospropofol 12.5 mg/kg (the maximum recommended dose) loss of consciousness takes about four minutes, compared to one circulatory time with propofol 2.5 mg/kg (the maximum recommended dose).
 Gan TJ (2006). "Pharmacokinetic and pharmacodynamic characteristics of medications used for moderate sedation". Clin Pharmacokinet 45 (9): 855–69. PMID 16928150