Fentanyl

Q; Fentanyl is? (select one) 

A) lipophilic 
B) hydrophilic


Answer: A

The objective of the above question is to emphasize the fact that though fentanyl is short-acting, due to its highly lipophilic state it rapidly gets distributed to highly perfused tissues i.e., brain, heart, kidney, and gastrointestinal tract followed by slower redistribution to muscle and fat tissues. This accumulated storage results in prolonged sedation and respiratory depression even when fentanyl is discontinued.

#pharmacology
#sedation
#analgesia


References:

1. Choi, Leena PhD; Ferrell, Benjamin A. MD; Vasilevskis, Eduard E. MD, MPH; Pandharipande, Pratik P. MD, MSCI; Heltsley, Rebecca PhD; Ely, E. Wesley MD, MPH; Stein, C. Michael MB, ChB; Girard, Timothy D. MD, MSCI - Population Pharmacokinetics of Fentanyl in the Critically Ill - Critical Care Medicine: January 2016 - Volume 44 - Issue 1 - p 64–72 

2. Kuip EJ, Zandvliet ML, Koolen SL, Mathijssen RH, van der Rijt CC. A review of factors explaining variability in fentanyl pharmacokinetics; focus on implications for cancer patients. Br J Clin Pharmacol. 2017;83(2):294–313. doi:10.1111/bcp.13129


3.Gourlay GK, Murphy TM, Plummer JL, Kowalski SR, Cherry DA, Cousins MJ: Pharmacokinetics of fentanyl in lumbar and cervical CSF following lumbar epidural and intravenous administration. Pain 1989; 38:253-9