hirudin and Skin-Diseases

Cutaneous reactions have been reported during anticoagulant therapy with coumarin derivatives, unfractionated and low molecular weight heparins, heparinoids, danaparoid and hirudins. Anticoagulant-induced skin reactions vary from local allergic manifestations to skin necrosis. In patients with allergic reactions, diagnosis and crossreactions between anticoagulants can be confirmed by intracutaneous testing. Coumarin- and heparin-induced skin necrosis are rare, but are important side effects due to their high morbidity and occasional mortality. Cutaneous tests are contraindicated in these patients. In the future, anticoagulant strategies may include direct synthetic thrombin inhibitors (argatroban and melagatran/ximelagatran) and the Factor Xa inhibitor, pentasaccharide (fondaparinux).

Topics: Anticoagulants; Coumarins; Female; Heparin, Low-Molecular-Weight; Hirudins; Humans; Middle Aged; Skin Diseases

Anticoagulant-induced skin reactions appear as allergic or necrotic responses to vitamin K antagonists or heparins. Cutaneous allergy has been reported with danaparoid sodium and flush reactions have been seen with hirudins. The pathogenesis of the reactions differs between drugs. Generally, they occur between days 3 to 10 after the start of treatment, but may also occur later. In patients experiencing necrosis with a vitamin K antagonist, concomitant protein C deficiency, protein S deficiency or lupus anticoagulant has been described, whereas the precise mechanism of the other reactions is unknown. In patients with allergic reactions to heparins, cutaneous tests may help to identify alternative anticoagulants. Such a test cannot be performed in patients with skin necrosis. In patients with heparin-induced skin reactions danaparoid sodium may be used after negative intracutaneous testing in some patients and a hirudin may be used without testing in all patients. Heparin-induced skin necrosis has been reported to be mediated by immunologic mechanisms and to be associated with a high frequency of heparin-induced thrombocytopenia type II. Surgical excision of the necrosis may be required. If further anticoagulation is indicated in any patient, extreme caution has to be taken when restarting oral anticoagulants. Because a large number of anticoagulants available today, safe treatment of all patients experiencing anticoagulant-induced skin reactions is feasible.

Topics: Anticoagulants; Coumarins; Fibrinolytic Agents; Heparin; Hirudins; Humans; Skin Diseases

The effects of antithrombotic drugs on random and free flap survival have been investigated in the past, but the experimental and clinical results are not in agreement. A perforator-based critical ischaemia model was used to evaluate the effects of different perioperatively administered pharmaceutical agents on tissue ischaemia and to assess the potential additional haemorheological or vasodilative effects of antithrombotics on flap microcirculation. Combined laser Doppler flowmetry and remission spectroscopy revealed an increase in certain microcirculation parameters in most groups in comparison with saline controls, and these changes correlated with flap survival. Clopidogrel and hirudin significantly improved the amount of viable flap tissue in comparison with controls, while unfractioned heparin had a negative effect on flap survival. Low molecular weight heparin, aspirin, pentoxifylline, and hydroxyethyl starch had no impact on the amount of viable flap tissue. A higher complication rate was observed in all experimental groups, but only clopidogrel had a negative impact on the flap viability. Our results add to the body of evidence supporting the conclusion that perioperative antithrombotic treatment improves flap survival. Clopidogrel and hirudin are effective pharmacological agents that significantly increased the viability of perforator-based skin flaps in rats, but at a higher risk of postoperative bleeding.

Topics: Animals; Aspirin; Clopidogrel; Disease Models, Animal; Fibrinolytic Agents; Graft Survival; Heparin; Hirudins; Ischemia; Laser-Doppler Flowmetry; Male; Microcirculation; Pentoxifylline; Postoperative Complications; Rats; Rats, Wistar; Skin Diseases; Skin Transplantation; Surgical Flaps; Ticlopidine

Topics: Adult; Anticoagulants; Female; Heparin; Hirudins; Humans; Injections, Subcutaneous; Pregnancy; Pregnancy Complications; Pregnancy Complications, Cardiovascular; Recombinant Proteins; Sarcoidosis; Skin Diseases; Thrombosis