Constant use of oral anticoagulants: implications in the control of their adequate levels.
BACKGROUND
Inappropriate and subtherapeutic anticoagulants dosages may result in severe thromboembolic and bleeding complications. The use of this treatment requires special attention and strict clinical and laboratory follow-up.


OBJECTIVE
To identify factors associated with appropriate control of the oral anticoagulant use, assessing the patients' knowledge and perception of the treatment.


METHODS
A cross-sectional study which included 140 patients followed in the oral anticoagulation outpatient clinic from November 2005 to June 2006. A structured questionnaire was drafted and applied to obtain the clinical characteristics of the patients and their knowledge about the treatment, their compliance with the treatment (Morisky s test) and their perception of the treatment.


RESULTS
The main indications for the use of oral anticoagulation therapy were atrial fibrillation (61.4%) and a prosthetic heart valve (55%). The duration of anticoagulation ranged from 24 to 72 months, and phenprocoumon (58%) was the most commonly used anticoagulant. As to the perception of the treatment, 95% of the patients mentioned concern about daily use of this medication. Periodic blood tests (21.4%) and the strict intake of oral anticoagulant (12.8%) were considered limiting factors. Adequate knowledge was outstanding in patients with an international normalized ratio (INR) outside the therapeutic range (64%), compared to patients with an INR within the therapeutic range (62%), as well as compliance with treatment in patients with an INR within the therapeutic range (54%), but with no statistical significance.


CONCLUSIONS
The results of this study show a prevalence of patients using oral anticoagulant with an INR within optimal values, although a high percentage of patients do not comply with the treatment. In this population it is clearly seen that they do not fully understand the treatment.
Esmerio
Francieli Giachini
FG
Instituto de Cardiologia do Rio Grande do Sul, Fundação Universitária de Cardiologia, Porto Alegre, RS, Brasil.
Souza
Emiliane Nogueira
EN
Leiria
Tiago Luz
TL
Lunelli
Rosana
R
Moraes
Maria Antonieta
MA
D000284:Administration, Oral; D000925:Anticoagulants / Q000008:administration & dosage*; D001281:Atrial Fibrillation / Q000188:drug therapy / Q000523:psychology*; D003430:Cross-Sectional Studies; D005260:Female; D007722:Health Knowledge, Attitudes, Practice; D006349:Heart Valve Diseases / Q000188:drug therapy / Q000523:psychology*; D006801:Humans; D019934:International Normalized Ratio; D008297:Male; D008875:Middle Aged; D016903:Drug Monitoring
D000925:Anticoagulants