2.4. Hirudin

Hirudin is a naturally occurring peptide in the salivary glands of medicinal leeches that irreversibly inhibits thrombin. Lepirudin, a recombinant hirudin derived from yeast cells, was used in clinical practice but is no longer available. Instead, the synthetic analog—bivalirudin (Angiox®)—with a short half-life is used at percutaneous coronary interventions and for treating patients with heparin-induced thrombocytopenia. The use of bivalirudin in patients with creatinine clearance below 30 mL/min is contraindicated [16].

### 2.5. Argatroban

Argatroban (Argatra®) is a synthetic reversible direct thrombin inhibitor. It is metabolized solely in the liver and is, therefore, suitable for patients with renal failure. It is used in patients with heparin-induced thrombocytopenia. Treatment with argatroban requires laboratory monitoring with activated partial thromboplastin time (APTT) and the dose adjusted to reach 1.5– 3.0 times prolonged baseline APTT, but should not exceed 100 s [17].
