Anti-Xa
Medical abbreviation · Laboratory Test
| Stands for | Anti-factor Xa assay |
|---|---|
| Categories | Medical |
Anti-Xa stands for Anti-factor Xa assay, a laboratory test abbreviation.
Chromogenic test that measures how strongly a patient's plasma inhibits factor Xa, used to quantify heparin and low-molecular-weight heparin and, with drug-specific calibrators, levels of apixaban, rivaroxaban and edoxaban. Heparin results are reported in international units per milliliter.
Example: Anti-Xa 0.42 IU/mL on the heparin nomogram; no rate change needed.
Usage notes
For twice-daily enoxaparin, a commonly cited therapeutic peak is 0.5 to 1.0 IU/mL drawn about four hours after a dose. Monitoring is mainly advised in pregnancy, obesity, kidney impairment and children, where weight-based dosing alone is unreliable. Many hospitals titrate unfractionated heparin infusions to anti-Xa levels, often 0.3 to 0.7 IU/mL, instead of the aPTT.
Related abbreviations
More laboratory test abbreviations
- ALC – Absolute lymphocyte count
- ALP – Alkaline phosphatase
- ALT – Alanine aminotransferase
- ANA – Antinuclear antibody
- ANC – Absolute neutrophil count
- anti-CCP – Anti-cyclic citrullinated peptide antibody
- ApoB – Apolipoprotein B
- aPTT – Activated partial thromboplastin time
- ASO – Antistreptolysin O
- AST – Aspartate aminotransferase
- BCx – Blood cultures
- BE – Base excess
See all 135 laboratory test abbreviations →
This entry is for general education and is not medical advice. Abbreviation use varies between institutions; always confirm in context.