[Treatment for overdose of oral anticoagulants]. / Tratamento da superdosagem de anticoagulantes orais.

PURPOSE: To evaluate the response of 73 patients with antivitamin K (AVK) overdose to 3 different therapeutic regimens. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Tratamento da superdosagem de anticoagulantes orais / Reversal of excessive oral anticoagulation

OBJETIVO - Verificar a resposta de 73 pacientes com superdosagem de droga anti-vitamina K (AVK) a 3 esquemas de tratamento. MÉTODOS - Os 73 pacientes foram avaliadois em 94 ocasiöes e divididos em 3 grupos: grupo A (N=32), suspensäo por dois dias e introduçäo de dose menor; grupo B (N=37), suspensÝo do AVK e reavaliaçäo em 4 dias; grupo C (N=25), vitamina K por via oral. A razäo normalizada internacional (RNI) final foi considerada adequada quando entre 2,0 e 4,0. RESULTADOS - Näo houve diferença entre os tratamentos (x2=2,352, p=0,671) para 61 pacientes com RNI inicial menor que 8. Houve mais pacientes com RNI menor que 2 no grupo C (x2=9,998, p=0,007) entre 33 pacientes com RNI maior que 8. Cinco dos 7 pacientes do grupo B que continuaram com superdosagem tinham RNI menor que 4,5 e pequeno risco de hemorragia. Entretanto 6, dos 10 pacientes do grupo C com anticoagulaçäo insuficiente tinham RNI menor que 1,6 e risco de trombose. Treze pacientes sangraram, mas sem necessidade de transfusäo. Conclusäo - A reversäo da superdosagem de AVK pode ser feita pela suspensäo de transfusÝo da droga Administraçäo de vitamina K, por via oral, deve ser restringir a pacientes com RNI mais elevado para se evitar anticoagulaçäo insuficiente.

[Clinical and laboratory evaluation of patients treated with oral anticoagulation]. / Avaliação clínica e laboratorial de pacientes em uso de anticoagulantes orais.

PURPOSE: To evaluate the clinical and laboratory management of patients taking anti-vitamin K drugs (AVK). METHODS: We studied retrospectively 952 visits of 100 outpatients taking AVK drugs for 7.6 months. There were 56 men and 44 women, 54 patients had acute arterial occlusion, 34 presented venous thromboembolism and 12 had cardiopathy. Anticoagulation level was estimated by the prothrombin time reported as international normalized ratio (INR). RESULTS: Seventy-three patients were considered stable, as they had one visit every at least 3 weeks, and their INR was within the therapeutic range in 59% of their visits, whereas 27 patients were less stable and had 36% of their visits within the therapeutic range. Insufficient anticoagulation was due to poor compliance (22%), vitamin K rich diet (19%) and underdosage (16%). Four patients presented minor bleedings, and there was no recurrence of thromboembolism. CONCLUSION: Careful clinical and laboratory management, using the INR, are necessary to avoid hemorrhage and thrombotic complications in patients taking oral anticoagulants.

Avaliaçäo clínica e laboratorial de pacientes em uso de anticoagulantes orais / Clinical and Laboratory Management of Patients Under Oral Anticoagulation

Objetivo - Avaliar o acompanhamento clínico e laboratorial de pacientes em uso de drogas antivitamina K(AVK). MÉTODOS - Foram avaliados, retrospectivamente, 952 consultas ambulatoriais de 100 pacientes em uso de AVK, durante 7,6 meses. Havia 56 homens e 44 mulheres, 54 pacientes com obstruçäo arterial aguda, 34 com troboembolismo venoso e 12 com cardiopatia. O nível de anticoagulaçäo foi medido pelo tempo de protrombina expresso em razäo normalizada internacional (RNI). RESULTADOS - Nível adequado de anticoagulaçäo foi observado em 59 "por cento" das consultas dos 73 pacientes considerados estáveis, com intervalo entre consultas maior do que 3 semanas. Os 27 pacientes instáveis tinham 36 "por cento" das consultas com RNI adequado. Anticoagulaçäo insuficiente ocorreu por uso irregular (22 por cento), dieta rica em vitamina (19 por cento) e dose insuficiente (16 por cento). Quatro pacientes tiveram sangramento sem gravidade e näo houve recorrência da trombose durante o período de observaçäo. CONCLUSÄO - O controle clínico e laboratorial, através do RNI, é fundamental para evitar complicaçöes hemorrágicas ou trombóticas em pacientes que necessitam de anticoagulaçäo oral.

Hemorrhagic and thrombotic complications in patients with myeloproliferative diseases.

OBJECTIVE: To correlate the incidence of hemorrhage and thrombosis to bleeding time (BT) and platelet aggregation in 27 consecutive patients with myeloproliferative diseases (MPD). DESIGN: Retrospective study. SETTING: Public tertiary referral center. PATIENTS: Eighteen patients with chronic myelogenous leukemia (CML), 5 with polycytemia vera (PV), 2 with essential thrombocytemia (ET) and 2 with idiopathic myelofibrosis (MF). Duke's BT and epinephrine-induced platelet aggregation were performed on the patients and on 10 healthy individuals. RESULTS: Eleven patients presented symptoms (41%):9 with hemorrhage (33%) and 5 with thrombosis (19%). There were less symptomatic patients in the CML group (28%) than in the other MPD (67%), without statistical significance (Fisher, p = 0.06). Duke's BT was longer in symptomatic patients (Mann-Whitney, p < 0.05). Platelet aggregation was abnormal in 7 patients (26%) and 71% of them were symptomatic (Fisher, p = 0.07). CONCLUSIONS: The high incidence of bleeding and thrombosis in patients with MPD was related to prolonged BT, but not to platelet aggregation abnormalities.