Analysis of acenocoumarol and levofloxacin interaction in elderly institutionalized patients

To analyze the interaction between acenocoumarol and  levofloxacin in the elderly. We also assessed how hypoalbuminemia affects international normalized ratio variation.

Retrospective study carried on elderly institutionalized patients who were prescribed levofloxacin concomitantly with acenocoumarol.  International normalized ratio variation during levofloxacin treatment was analyzed with the t-Student test. Correlation between albuminemia and international normalized ratio variation was calculated using Pearson´s correlation coefficient.

The mean international normalized ratio previous to treatment with levofloxacin was 2.5 (standard deviation: 0.6) and during treatment it was  4.7 (standard deviation: 1.9) (p < 0.05). In 54.3% of the cases, the  international normalized ratio value was equal to or greater than 4.5. Not  linear association between albuminemia and international normalized ratio  increase was found using Pearson´s test (R = -0.16).

In more than half of the occasions international normalized ratio raised to clinically rellevant values (≥ 4.5). No influence of hypoalbuminemia in the increase in international normalized ratio was shown.