Does probiotic treatment with Lactobacillus rhamnosus + Bifidobacterium longum (Bifolac) interact p

Fråga: Does probiotic treatment with Lactobacillus rhamnosus + Bifidobacterium longum (Bifolac) interact pharmacologically with warfarin?

Sammanfattning: There are no reports of a pharmacologic interaction between probiotics and warfarin, but theoretically probiotic therapy could influence warfarin dose requirements by altering the intestinal levels of vitamin K.

Svar: Bifolac is a probiotic used for normalisation of the intestinal bacterial flora, in episodes of diarrhoea or prophylactic. Its potential for drug interactions has not been investigated (1).

A sizeable part of the vitamin K absorbed in the gut is produced by gut bacteria and antibiotic-induced disturbances of the intestinal flora has been associated with symptomatic vitamin K deficiency and severe haemorrhage (2,3). Hence, it is theoretically possible that administration of bacteria could alter the local production of vitamin K and the sensitivity to vitamin K antagonists such as warfarin.

Animal studies indicate that B. longum lacks the ability to synthesize vitamin K (4), and in vitro the bacterium actually has the ability to reduce the vitamin K levels of the growth medium. Vitamin K is a growth factor for many bacteria strains and since B. longum requires only small amounts of vitamin K for its growth its apparent consumption of vitamin K has been interpreted as a means of competing with other bacteria more dependent on vitamin K for their growth (5). Although this offers a theoretical mechanism for drug interactions with vitamin K antagonists, the potential clinical importance remains to be elucidated. We found no specific information regarding the role of L. rhamnosus in the synthesis or intestinal turnover of vitamin K.

We recommend careful INR monitoring in warfarin-treated patients starting medication with Bifolac. SPC Bifolac (2009-02-17) Bentley R, Meganathan R. Biosynthesis of vitamin K (menaquinone) in bacteria. Microbiol Rev 1982;46(3):241-280 Resta SC. Effects of probiotics and commensals on intestinal epithelial physiology: implications for nutrient handling. J Physiol 2009;587(Pt 17):4169-4174 Kindberg C, Suttie JW, Uchida K, Hirauchi K, Nakao H. Menaquinone production and utilization in germ-free rats after inoculation with specific organisms. J Nutr 1987;117(6):1032-1035 Hojo K, Nagaoka S, Murata S, Taketomo N, Ohshima T, Maeda N. Reduction of vitamin K concentration by salivary Bifidobacterium strains and their possible nutritional competition with Porphyromonas gingivalis. J Appl Microbiol 2007;103(5):1969-1974