t1/2
Medical abbreviation · Pharmacology
| Stands for | Half-life |
|---|---|
| Categories | Medical |
t1/2 stands for Half-life, a pharmacology abbreviation.
Time it takes for the concentration of a drug in the blood to fall by half. It determines how often a drug must be dosed, how long it takes to reach steady state and how long effects persist after stopping.
Example: Amiodarone t1/2 averages about 58 days, so interactions persist for months after stopping.
Usage notes
Also written t½. A drug reaches about 97 percent of steady state after five half-lives, and is about 97 percent eliminated five half-lives after the last dose. Half-life depends on both volume of distribution and clearance, so it lengthens in kidney or liver failure for many drugs.
Related abbreviations
More pharmacology abbreviations
- ADA – Anti-drug antibodies
- ADE – Adverse drug event
- ADME – Absorption, distribution, metabolism and excretion
- ADR – Adverse drug reaction
- AE – Adverse event
- ATC – Anatomical Therapeutic Chemical classification
- AUC – Area under the curve
- BAN – British Approved Name
- BBW – Black box warning
- BE – Bioequivalence
- Cmax – Maximum concentration
- Css – Steady-state concentration
See all 36 pharmacology abbreviations →
This entry is for general education and is not medical advice. Abbreviation use varies between institutions; always confirm in context.