Treatment for overdose of oral anticoagulants
Lourenço, D.M.; Morelli, V.M.; Vignal, C.V.
Arquivos Brasileiros de Cardiologia 70(1): 9-13
1998
ISSN/ISBN: 0066-782X PMID: 9629681 Document Number: 485856
To evaluate the response of 73 patients with antivitamin K (AVK) overdose to 3 different therapeutic regimens. Seventy three patients were evaluated in 94 occasions: group A (N = 32), consisted of drug withdrawal for 2 days followed by reduced dosage; group B (N = 37), drug withdrawal and reassessment within 4 days; group C (N = 25), oral administration of vitamin K. Therapeutic range was set between INR-values of 2 and 4. Reversal regimens did not result in differences among 61 patients who had initial INR < 8 (chi 2 = 2.352, p = 0.671). There were more patients bellow therapeutic range in group C (N = 14) than group B (N = 19) (chi 2 = 9.998, p = 0.007). After intervention, 7 patients in group B still had INR > 4, but 5 of them were bellow 4.5, without increased bleeding risk. There were 10 patients in group C bellow therapeutic range, 6 of them with INR < 1.6, with risk of thromboembolism. Thirteen patients bled, but none required transfusion. Reversal of excessive oral anticoagulation can be safely performed by initial withdrawal of the drug, followed by lower doses. Vitamin K administration may lead to INR bellow the therapeutic range. This should be reserved for patients with high INR or in the presence of bleeding.