Dosing and scheduling
Steady State
Last updated
The point at which the amount of compound going in over a period equals the amount the body clears over that same period, so the level stops climbing and settles into a repeating pattern. Before steady state, each dose leaves a little more behind than the one before it. Reaching it depends on how fast the compound clears and on the dosing continuing unchanged.
Why it matters here
Effects measured early in a programme may simply reflect a level that has not finished rising, so an early reading and a later one can differ with no change in dose at all. If dosing stops, restarts or is missed, the level starts moving again and the programme is no longer at steady state.
What it is not
Saturation of the blood level is not saturation of the target. Steady state describes how much compound is present, whereas receptors may be fully occupied well below that level or never fully occupied at all, so a higher steady level does not automatically mean a stronger effect.
Also called
- steady state
- steady-state
- steady levels
- saturation
- saturated
- saturation point
- accumulation
- built up
- loaded up
- plateau
- plateaued
- levelled off
- equilibrium
Saturation and loaded up are the informal names, and both suggest a container filling, which is misleading. Nothing is being filled: intake and clearance have simply come into balance.
Compounds carrying this term
None on file yet. This term is in the controlled vocabulary but no compound record currently uses it — which is a statement about our coverage, not about the term.