Overanticoagulation associated with combined use of lactulose and acenocoumarol or phenprocoumon

Article date: April 2004

By: Loes E. Visser, Fernie J. A. Penning‐van Beest, J. H. P. Wilson, Arnold G. Vulto, A. A. Harrie Kasbergen, Peter A. G. M. De Smet, Albert Hofman, Bruno HCh Stricker, in Volume 57, Issue 4, pages 522-524

Some medical textbooks on drug interactions take note of the potential interaction between laxatives and coumarin anticoagulants, but epidemiological evidence that this interaction is of practical importance is lacking. We conducted a follow‐up study in a large population‐based cohort to investigate which laxatives are associated with overanticoagulation during therapy with coumarins. Of the 1124 patients in the cohort, 351 developed an International Normalized Ratio ≥ 6.0. The only laxative with a moderate but significantly increased relative risk of overanticoagulation was lactulose (relative risk 3.4, 95% confidence interval 2.2, 5.3). In view of the widespread use of lactulose, especially among the elderly, awareness of this potential drug interaction is required.

DOI: 10.1046/j.1365-2125.2003.02036.x

View this article