Nutritional Supplement
Cranberry
Negative Interactions
1- Potential Negative Interaction
Cranberry
Warfarin
There have been at least five case reports suggesting that cranberry juice increases the activity of warfarin, possibly by inhibiting the breakdown of warfarin in the body. Because of this potential interaction, people taking warfarin should avoid, or limit the intake of, cranberry juice. The U.K. Medicines Authority has advised people taking warfarin to avoid cranberry juice.
WarfarinCranberry- No authors listed. Possible interaction between warfarin and cranberry juice. Curr Prob Pharmacovigilance 2003;29:8.
Supportive Interactions
2- Support Medicine
Cranberry
Lansoprazole
Omeprazole was shown to reduce protein-bound vitamin B12 absorption and cranberry (Vaccinium macrocarpon) juice was shown to increase protein-bound vitamin B12 absorption in eight people treated with omeprazole (a drug closely related to lansoprazole). While this effect has not been studied with lansoprazole, people taking lansoprazole may choose to drink cranberry juice or other acidic liquids with vitamin B12-containing foods. Unlike vitamin B12 found in food, vitamin B12 found in supplements is not bound to peptides (pieces of protein). The absorption of B12 supplements therefore does not require acid and is unlikely to be improved by drinking cranberry juice.
LansoprazoleCranberry- Saltzman JR, Kemp JA, Golner BB, et al. Effect of hypochlorhydria due to omeprazole treatment or atrophic gastritis on protein-bound vitamin B12 absorption. J Am Coll Nutr 1994;13:584-91.
- Reduce Side Effects
Cranberry
Omeprazole
People taking omeprazole may increase absorption of dietary vitamin B12 by drinking cranberry (Vaccinium marocarpon) juice or other acidic liquids with vitamin B12-containing foods.
OmeprazoleCranberry- Saltzman JR, Kemp JA, Golner BB, et al. Effect of hypochlorhydria due to omeprazole treatment or atrophic gastritis on protein-bound vitamin B12 absorption. J Am Coll Nutr 1994;13:584-91.