Effect of ramadan fasting on acenocoumarol-induced antocoagulant effect.

Eating patterns, food intake and type of alimentation vary greatly during the month of ramadan. Furthermore, fasting, which practiced during the month of ramadan, can have an impact on drug's metabolism. These two factors, fasting and eating habits changes during the month of ramadan, may impact acenocoumarol anticoagulant effect, translated by variations of INR values. The aim of our study was to see ramadan fasting effects on INR variations in patients treated by acenocoumarol. A prospective monocentric study was conducted during the ramadan month on fasting outpatients that were treated by acenocoumarol. Baseline INR values (e.i. most recent available value before the month of ramadan) were compared to INR values obtained during the month of ramadan. All patients were monitored for signs of secondary haemorrhagic complications linked to treatment by anti-vitamin K (AVK). Thirty patients were included in the study with a sex ratio 1. Patients mean age was 65 years. Around two thirds of the patients were treated by AVK for atrial fibrillation. The majority of patients (94%) have been treated by AVK for more than a year. Mean INR was significantly higher during the month of ramadan than baseline (3.51 vs 2.52; p< 0.0001). There were also more overdoses during the month of ramadan than baseline (9 vs. 0; p=0.014). The increased INR values highlights the need of a close monitoring of INR values during the month of ramadan, particularly in patients with a high haemorrhagic risk.