sentences:  As they are administered by injection (intravenous, intramuscular or subcutaneous), they are less suitable for long-term treatment.Argatroban (as well as the hirudins) is used for heparin-induced thrombocytopenia, a relatively infrequent yet serious complication of heparin treatment that requires anticoagulation (as it increases both arterial and venous thrombosis risk) but not with the causative agent, heparin.Ximelagatran showed good efficacy compared with warfarin in several trials in prevention and treatment of deep vein thrombosis and as thromboprophylaxis in atrial fibrillation.