How long can fentanyle and versed stay in your system after a colonoscopy?

Versed and Fentanyl: The half life of fentanyl is about seven hours. The half life of versed is more variable, about 2 - 6 hours. In 5 half lives, or 10 - 35 hours, both drugs will be largely eliminated. Chronic users may eliminate the drugs more slowly as they may have fat storeage of the drugs before colonoscopy.

6-8 hours: The clinical effects, meaning sedation and pain relief, may not be apparent but the metabolites and their effects are still in your bloodstream. Other factors can influence how long these meds have an effect and stay in your body. This is why as a general rule, patients are given a full 24 hours to have them clear from their systems.