Home Wiki Studies Forum Groups Blog Video Images News Chat
Go Back   Drugs Forum > DRUG-FORUMS > Opiates & Opioids
Mark Forums Read
Register Tags


Opiates & Opioids Opiates & Opioids.

Thread Tools
Old 20-05-2012, 03:16
JasNod JasNod is offline
Join Date: 08-04-2012
23 y/o Male from United States
Posts: 7
JasNod is an unknown quantity at this point
Points: 28, Level: 1 Points: 28, Level: 1 Points: 28, Level: 1
Activity: 0% Activity: 0% Activity: 0%
What is "terminal elimination half-life"?

What does terminal elimination half life mean? Is it when half the drug degrades like terminal half life, or is it when enough half lives have passed that the drug is fully dissintegrated? I read: "fentanyl has a terminal elimination half-life of 219 minutes". Sorry for any typos I'm on a phone.

Post Quality Reviews:
Thanks for asking this.
Old 22-05-2012, 19:36
Tigey Tigey is offline
Account Awaiting Email Confirmation.
Join Date: 05-11-2011
Male from Australia
Posts: 278
Blog Entries: 1
Tigey must live here.Tigey must live here.Tigey must live here.Tigey must live here.Tigey must live here.Tigey must live here.Tigey must live here.
Points: 1,034, Level: 4 Points: 1,034, Level: 4 Points: 1,034, Level: 4
Activity: 0% Activity: 0% Activity: 0%
Re: What is "terminal elimination half-life"?

Good question. To quote:

Terminal plasma half-life is the time required to divide the plasma concentration
by two after reaching pseudo-equilibrium, and not the time required to
eliminate half the administered dose. When the process of absorption is not a
limiting factor, half-life is a hybrid parameter controlled by plasma clearance
and extent of distribution. In contrast, when the process of absorption is a
limiting factor, the terminal half-life reflects rate and extent of absorption and
not the elimination process (flip-flop pharmacokinetics). The terminal half-life is
especially relevant to multiple dosing regimens, because it controls the degree of
drug accumulation, concentration fluctuations and the time taken to reach
(full document attached).

As best as I can explain it, after peak plasma concentration of a drug, the drug starts exiting your system.
At this point, the drug is exiting fast (units of flow). At a point called the terminal phase, the drug starts exiting at a steady rate, and this gives the 'curve then straight line slope' look familiar to you if you've seen a drug in blood plasma concentration graph before. The terminal elimination half-life is the time it takes to lower the amount of drug in plasma by half (divide it by two), after it has reached steady-state absorption or steady-state plasma clearance/distribution. In other words, there are three limiting factors in how fast your body can absorb drugs, and this measure gives you a good baseline for re-dosing etc.

read the full text for a better explanation - it's 3.30am here!

hope that helps,


Post Quality Reviews:
Good answer. Thanks for that, and documented too.
Attached Files
File Type: pdf Plasma_terminal_half-life.pdf (510.0 KB, 11 views)

Share this on:

Thread Tools

» New Threads
Watching your girlfriend getting...
Last post by idfma
78 Replies, 25,189 Views
MDMA turned black
Last post by Boavida
0 Replies, 7 Views
Why coke above other stimulants?
Last post by Nosferatus
5 Replies, 273 Views
Path to Addiction?
Last post by Beyondcold
3 Replies, 131 Views
I am on DAY 3 off heavy opiate use
Last post by cbabycee
122 Replies, 13,612 Views
If you had a blank script for any...
Last post by idfma
3 Replies, 193 Views
No idea how I got here, feeling a...
Last post by cbabycee
152 Replies, 18,247 Views
Best ways to use MSContin,...
Last post by Benzocodone
23 Replies, 67,886 Views
Loperamide. Is this my addiction...
Last post by Chix757
138 Replies, 10,616 Views
Morphine Sulfate ER 60mg 'E 60'
Last post by Benzocodone
2 Replies, 227 Views
» New Wiki Articles

Sitelinks: Information:

All times are GMT +1. The time now is 17:38.

Copyright: SIN Foundation 2003 - 2014, All rights reserved