Abstract van de publicatie betreffende de vergelijking tussen marcoumar en sintrom

 

THERAPEUTIC QUALITY CONTROL OF ORAL ANTICOAGULANT THERAPY COMPARING THE SHORT-ACTING ACENOCOUMAROL AND THE LONG-ACTING PHENPROCOUMON

 

Alain P.A. Gadisseur, Felix J.M. van der Meer, Henk J. Adriaansen, Stephan D. Fihn, Frits R. Rosendaal.

 

The Netherlands two coumarins are routinely used for oral anticoagulant therapy (OAT), the short-acting acenocoumarol (t ½ = 11 hrs), and the long-acting phenprocoumon (t ½ = 140 hrs). To investigate if the different pharmacokinetics of these coumarins result in a different quality of anticoagulation we studied patients from the Leiden anticoagulation clinic treated with acenocoumarol or phenprocoumon in 1998-1999 with a treatment duration of more than 16 weeks. Out of 1368 eligible patients 228 pairs could be closely matched for indication for anticoagulant therapy, age, sex and date of start of treatment. As a validation test a similar analysis was carried out on 51 matched patient pairs at a second anticoagulation clinic.

 

456 patients with 7245 INR checks yielded 230 patient-years. The quality of OAT calculated over the whole treatment period was higher in patients treated with phenprocoumon as expressed by number of INR checks in the therapeutic range (phenprocoumon: 42.7%, acenocoumarol: 36.5%, difference: 6.1%, CI95 of the difference: 3.0 - 9.3%) and by time in range (phenprocoumon: 46.6%, acenocoumarol: 41.6%, difference: 5.0%, CI95 of the difference: 1.3 – 8.6%). After the initial 6 weeks of OAT, when a more stable effect should have been reached, the differences became more pronounced (difference: 6.1%, CI95: 1.8 – 10.4%).

 

The incidence of severe bleeding complications was similar (phenprocoumon: 0.04/patient/year vs. acenocoumarol: 0.03/patient/year) with a slight excess of minor bleeds with phenprocoumon (0.19/patient/year vs. 0.06/patient/year). There was 1 non-fatal pulmonary embolism in the phenprocoumon group (0.009/patient/year) against 2 fatal pulmonary emboli in the acenocoumarol group (0.017/patient/year).

 

We conclude that phenprocoumon leads to a better quality of OAT than acenocoumarol. As there is no difference in major bleeding complications and only a small difference in minor bleeding complications phenprocoumon is preferable to acenocoumarol for prolonged OAT.