Hirudin

Class Direct thrombin inhibitor
Chemistry

Polypeptide

Routes of administration

Topical and IV

Absorption

Oral bioavailability 10%

Solubility

pKa values of about 7.1, 8.4, and 9.2. good water solubility

Distribution

VOD=0.3L/kg; minimally protein bound (only to thrombin)

Metabolism

Minimally metabolised; some hydrolysis in the liver occurs, whcih liberates [eptide fragments and amino acids

Elimination

90% of the drug is cleared renally.
Monitored by APTT or ECT(ecarin time)

Time course of action

Half life is about 0.8-1.7 hrs

Target receptor

Thrombin

Mechanism of action

Binds to thrombin, deactivating it and preventing the formation of fibrin (as well as inhibiting other thrombin-driven parts of haemostasis, such as the activation of platelets)

Clinical effects

Anticoagulation is the only clinically apparent effect; no significant side effects apart from bleeding complications

Literature reference

Greinacher et a, 1991

CICM details of understanding Not specifically listed in the CICM syllabus
Mentioned around Deranged Physiology
Related SAQs