Interactions with Drugs

In theory, due to its acidic pH, cranberry juice may counteract antacids. Cranberry juice theoretically may increase the effects of antibiotics in the urinary tract and increase the excretion of some drugs in the urine. Cranberry juice may increase absorption of vitamin B12 in patients using proton pump inhibitors such as esomeprazole (Nexium®).

Some cranberry tinctures may have high alcohol content and may lead to vomiting if used with the drug disulfiram (Antabuse®) or metronidazole (Flagyl®).

Although it is controversial, some studies have shown that taking the prescription blood thinner warfarin (Coumadin®) and cranberry products at the same time can elevate the international normalized ratio (INR), which could increase the risk of bleeding.

Interactions with Herbs and Dietary Supplements

In theory, cranberry juice may increase the excretion of some herbs or supplements in the urine.

Theoretically cranberry products may increase the risk of bleeding in people taking other herbs or supplements like garlic or danshen.

Inhibition of H. pylori bacteria, which may lead to gastrointestinal ulcers, may be increased when oregano and cranberry are taken together.

Acidifiers, Alzheimer's agents, antibacterials, antifungals, antihelminthics (expels worms), antilipemics (cholesterol-lowering agents), antineoplastics (anticancer agents), antioxidants, antiparasitics, antiulcer agents, antivirals, cytochrome P450-metabolized agents (agents broken down by the liver), diuretics, gastrointestinal agents, hypoglycemics (blood sugar lowering), lingonberry, renally eliminated agents (agents eliminated by the kidneys), salicylate-containing agents, vitamin B12.

This evidence-based monograph was prepared by The Natural Standard Research Collaboration