Thrombin Activity and Oral Anticoagulant Therapy: A Further Evaluation

Duration and discontinuation of oral anticoagulant therapy in the prophylaxis of recurrent thrombembolic diseases is often discussed. After stopping of the therapy an elevated incidence of rethromboses are observed. Therefore we determined fibrinopeptide A (FPA) as the most sensitive parameter of thrombin activity in vivo in patients treated with phenprocoumon in order to get information on the effectivity of the oral anticoagulant therapy and on the rebound phenomenon after discontinuation of the treatment.In 136 outpatients a significant relation between FPA and the effectivity of the anticoagulant therapy was observed: 2.7 ng/ml plasma (mean, thrombotest values < 5%), 3.5 ng/ml (5%-15%) and 4.1 ng/ml (>15%, p < 0.01). Normal FPA were 1.4ng/ml. In 11 patients with low FPA the oral anticoagulants were discontinued. FPA was determined in weekly intervalls. Within four weeks a continous increase of FPA from 1.6 ng/ml (median) to 3.8 ng/ml was observed. After eight weeks FPA was 8.2 ng/ ml (p < 0.05). The in vitro release of FPA after 10 min incubation of blood increased from 3.4ng/ml to 72 ng/ml after eight weeks (p < 0.05, normal release up to 5 ng/ml).The data indicate the clinical relevance and the different therapeutic implications of the determination of FPA in patients treated with phenprocoumon. They further give the first criterion, which outlines the effectivity of an oral anticoagulation therapy by reducing the thrombin activity in vivo. They give some evidence for a rebound like phenomenon after discontinuation of the oral anticoagulant treatment.

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Thrombin Activity and Oral Anticoagulant Therapy: A Preliminary Study

Pathophysiology of Haemostasis and Thrombosis ◽

10.1159/000215907 ◽

1989 ◽

Vol 19 (3) ◽

pp. 142-146

Author(s):

F. Marongiu ◽

G.G. Sorano ◽

G. Mameli ◽

A.M. Mamusa ◽

A.B. Cambuli ◽

...

Keyword(s):

Anticoagulant Therapy ◽

Oral Anticoagulant ◽

Oral Anticoagulant Therapy ◽

Thrombin Activity ◽

Preliminary Study

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Outcomes of Oral Anticoagulant Therapy Managed by Telephone vs In-Office Visits in an Anticoagulation Clinic Setting

Yearbook of Pulmonary Disease ◽

10.1016/s8756-3452(08)70664-9 ◽

2008 ◽

Vol 2008 ◽

pp. 219-220 ◽

Cited By ~ 1

Author(s):

K.L. Lewis

Keyword(s):

Anticoagulant Therapy ◽

Oral Anticoagulant ◽

Oral Anticoagulant Therapy ◽

Anticoagulation Clinic ◽

Office Visits ◽

Clinic Setting

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Confusion Over the Therapeutic Range for Monitoring Oral Anticoagulant Therapy in North America

Thrombosis and Haemostasis ◽

10.1055/s-0038-1642740 ◽

1988 ◽

Vol 59 (02) ◽

pp. 129-132 ◽

Cited By ~ 24

Author(s):

J Hirsh ◽

M Levine

Keyword(s):

North America ◽

Anticoagulant Therapy ◽

Therapeutic Range ◽

Oral Anticoagulant ◽

Oral Anticoagulant Therapy

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Controlled Trial of the Sequential Use of Streptokinase and Ancrod in the Treatment of Deep Vein Thrombosis of Lower Limb

Thrombosis and Haemostasis ◽

10.1055/s-0038-1649223 ◽

1977 ◽

Vol 37 (02) ◽

pp. 222-232 ◽

Cited By ~ 12

Author(s):

D. A Tibbutt ◽

C. N Chesterman ◽

E. W Williams ◽

T Faulkner ◽

A. A Sharp

Keyword(s):

Deep Vein Thrombosis ◽

Clinical Improvement ◽

Anticoagulant Therapy ◽

Lower Limb ◽

Oral Anticoagulant ◽

Controlled Trial ◽

Oral Anticoagulant Therapy ◽

Control Group ◽

Vein Thrombosis ◽

Deep Vein

SummaryTreatment with streptokinase (‘Kabikinase’) was given to 26 patients with venographically confirmed deep vein thrombosis extending into the popliteal vein or above. Treatment was continued for 4 days and the patients were allocated randomly to oral anticoagulant therapy or a course of treatment with ancrod (‘Arvin’) for 6 days followed by oral anticoagulant therapy. The degree of thrombolysis as judged by further venographic examination at 10 days was not significantly different between the 2 groups. The majority of patients showed clinical improvement but there was no appreciable difference between the groups at 3 and 6 months. Haemorrhagic complications were a more serious problem during the period of treatment with ancrod than during the equivalent period in the control group.

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Relationship Between Total Prothrombin, Native Prothrombin and the International Normalized Ratio (INR)

Thrombosis and Haemostasis ◽

10.1055/s-0038-1656342 ◽

1992 ◽

Vol 68 (02) ◽

pp. 160-164 ◽

Cited By ~ 3

Author(s):

P J Braun ◽

K M Szewczyk

Keyword(s):

Anticoagulant Therapy ◽

Oral Anticoagulant ◽

Inverse Relationship ◽

Low Dose ◽

Oral Anticoagulant Therapy ◽

International Normalized Ratio ◽

Antigen Assay ◽

Dose Oral ◽

Anticoagulated Patients ◽

Sensitive Method

SummaryPlasma levels of total prothrombin and fully-carboxylated (native) prothrombin were compared with results of prothrombin time (PT) assays for patients undergoing oral anticoagulant therapy. Mean concentrations of total and native prothrombin in non-anticoagulated patients were 119 ± 13 µg/ml and 118 ± 22 µg/ml, respectively. In anticoagulated patients, INR values ranged as high as 9, and levels of total prothrombin and native prothrombin decreased with increasing INR to minimum values of 40 µg/ml and 5 µg/ml, respectively. Des-carboxy-prothrombin increased with INR, to a maximum of 60 µg/ml. The strongest correlation was observed between native prothrombin and the reciprocal of the INR (1/INR) (r = 0.89, slope = 122 µg/ml, n = 200). These results indicated that native prothrombin varied over a wider range and was more closely related to INR values than either total or des-carboxy-prothrombin. Levels of native prothrombin were decreased 2-fold from normal levels at INR = 2, indicating that the native prothrombin antigen assay may be a sensitive method for monitoring low-dose oral anticoagulant therapy. The inverse relationship between concentration of native prothrombin and INR may help in identification of appropriate therapeutic ranges for oral anticoagulant therapy.

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