[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Parenteral direct thrombin inhibitors](https://durgical.com/en/pharmacology/classes/parenteral-direct-thrombin-inhibitors/) › Argatroban [Pharmacology](https://durgical.com/en/pharmacology/) · [Parenteral direct thrombin inhibitors](https://durgical.com/en/pharmacology/classes/parenteral-direct-thrombin-inhibitors/) # Argatroban An intravenous anticoagulant that blocks thrombin directly. The usual choice when heparin-induced thrombocytopenia rules out heparin. Updated 2026-11-01 - Class: [Parenteral direct thrombin inhibitors](https://durgical.com/en/pharmacology/classes/parenteral-direct-thrombin-inhibitors/) - Enzyme: Thrombin (coagulation factor IIa) - ATC code: B01AE03 ## ⚠ High-alert medication An error with this medicine can cause serious harm: double checks and protocols are used. ✂**Thrombin (coagulation factor IIa)**Argatroban ⓘ The figure shows human thrombin with argatroban in its active site; in this crystal the catalytic serine was changed to alanine (S195A) to study binding. **Target in 3D:** Thrombin (coagulation factor IIa). PDB structure 4HFP (RCSB PDB, public domain). [View the structure at RCSB PDB](https://www.rcsb.org/structure/4HFP) · Drag to rotate · pinch to zoom ## Mechanism of action Argatroban is a small synthetic molecule that binds reversibly to the active site of thrombin, both free and clot-bound, without needing antithrombin. It blocks the reactions thrombin drives: fibrin formation, activation of factors V, VIII and XIII, activation of protein C and platelet aggregation. - Argatroban binds the active site of thrombin, reversibly - It needs no antithrombin and reaches clot-bound thrombin - Fibrin formation and thrombin-driven platelet activation stop ## Pharmacokinetics **Distribution** Mainly in the extracellular fluid; about half is bound to plasma proteins. **Metabolism** In the liver (hydroxylation and aromatisation); CYP3A4 takes part, but it is not a clinically important route. **Elimination** Mostly in the faeces, through the bile; no adjustment is needed in kidney impairment. **Half-life** Short: about 39 to 51 minutes; coagulation tests return to baseline within 2 to 4 hours after stopping. **Onset and duration** Immediate on starting the infusion. ## Indications - Prevention or treatment of thrombosis in heparin-induced thrombocytopenia. [Heparin-induced thrombocytopenia →](https://durgical.com/en/conditions/heparin-induced-thrombocytopenia/) - Anticoagulation during percutaneous coronary intervention in patients with or at risk of HIT. [Myocardial Infarction (Heart Attack) →](https://durgical.com/en/conditions/myocardial-infarction/) ## Adverse effects ### Common - Bleeding (gums, puncture sites, gut, urine) - Low blood pressure - Shortness of breath, fever, diarrhoea - Chest pain, back pain, nausea, headache (in PCI) ### Serious (rare, important) - Major and intracranial bleeding - Unexplained falls in haematocrit or blood pressure may signal hidden bleeding - Allergic reactions ## Contraindications - Major bleeding - Hypersensitivity to argatroban ## Key interactions **Heparin** Heparin's effect on the aPTT is allowed to wear off before argatroban starts. **Warfarin** Argatroban raises the PT and INR beyond warfarin alone; the switch follows a defined INR plan. **Antiplatelets, thrombolytics and glycoprotein IIb/IIIa blockers** Add to bleeding risk; combined use with thrombolytics or IIb/IIIa blockers is not established. ## What is monitored - aPTT, a few hours after starting and after every change - Liver function, which sets the starting regimen - Haemoglobin, haematocrit and signs of bleeding - INR during the transition to warfarin ## Administration and safety - Continuous intravenous infusion with a pump; some products are ready to use and some need dilution, so the label is read before preparing - Weight-based orders are checked by a second person (high-alert medicine) - Reduced starting regimen in liver impairment; avoided in PCI when liver impairment is significant - No specific antidote: excess effect is managed by stopping or slowing the infusion ## Nursing care - Baseline aPTT, platelet count, haemoglobin and liver function before starting - Draw the aPTT at the planned times and adjust only by protocol - Watch puncture sites, urine, stools and neurological status for bleeding - During warfarin overlap, interpret the INR knowing argatroban raises it ## Pregnancy and breastfeeding Limited published data have not linked it to fetal harm; untreated thrombosis and bleeding both carry risks in pregnancy. ## Memory aid ARGatroban for HIT: ARGinine-based, Really short, Goes out through the liver. ## Test yourself Think of the answer, then tap the question to see it. ## What is the main indication for argatroban? Prevention or treatment of thrombosis in heparin-induced thrombocytopenia, and anticoagulation during PCI in patients with or at risk of HIT. ## Which organ problem changes the argatroban regimen? Liver impairment, because argatroban is cleared by the liver; kidney impairment needs no adjustment. ## Which test is used to follow argatroban? The aPTT. [Add to my cards (3)](https://durgical.app/estudiar/?add=/en/pharmacology/argatroban/) ## Related drugs - [Heparin](https://durgical.com/en/pharmacology/heparin/) - [Warfarin](https://durgical.com/en/pharmacology/warfarin/) - [Dabigatran](https://durgical.com/en/pharmacology/dabigatran/) - [Bivalirudin](https://durgical.com/en/pharmacology/bivalirudin/) ## Related conditions - [Heparin-induced thrombocytopenia](https://durgical.com/en/conditions/heparin-induced-thrombocytopenia/) - [Myocardial Infarction (Heart Attack)](https://durgical.com/en/conditions/myocardial-infarction/) [← Back to the class: Parenteral direct thrombin inhibitors](https://durgical.com/en/pharmacology/classes/parenteral-direct-thrombin-inhibitors/) Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given. Sources: [DailyMed - ARGATROBAN injection, solution](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=629aee90-3bf3-4947-a978-21cbba2e1c41) (DailyMed (U.S. National Library of Medicine), 2026); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=B01AE&showdescription=no) (WHO Collaborating Centre for Drug Statistics Methodology, 2026); [4HFP: Structure of thrombin mutant S195a bound to the active site inhibitor argatroban](https://www.rcsb.org/structure/4HFP) (RCSB Protein Data Bank, 2013). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/pharmacology/argatroban/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/argatroban/