Does AZO Cranberry Interact With Any Medication?

In our latest question and answer, the pharmacist discusses interactions between cranberry and prescription/over-the-counter medications.

Question

I've had some UTIs in the past and was told that cranberry can help. I'm looking at the AZO cranberry supplement and want to make sure that it is safe to take with all my meds.

Asked by Dusty On Jan 05, 2023

Answered by
Medical Content Reviewed By HelloPharmacist Staff

Published Jan 05, 2023
Last updated May 05, 2024

Key points

  • Cranberry has a number of potential drug interactions, but most of them are considered relatively minor.
  • One drug that is considered to have a clinically significant interaction with cranberry is the anticoagulant warfarin.
  • Always be sure to let your doctor know of all the drugs and supplements you are taking so you can be appropriately monitored.

Thanks so much for reaching out to us!

Cranberry, which is popularly used in dietary supplements for supporting urinary health, does have some interactions that are important to be aware of.

Since you didn't provide your medication list, in the next sections, I'll breakdown the ingredients in the product you mentioned (AZO Cranberry) and discuss potential drug interactions

What Is In AZO Cranberry?

Azo Cranberry With Supplement Facts

AZO Cranberry contains a patented cranberry extract called Pacran, which is a 'whole cranberry' extract (500mg).

It also contains several other ingredients used in the manufacturing of the product (such as soybean oil, gelatin, yellow beeswax, etc...) but what we are concerned about here is the cranberry content.

It can sometimes be difficult to determine potential drug interactions with dietary supplements since they often contain several ingredients, but in this case, there is only one we are discussing.

Cranberry Drug Interactions

Cranberry has several potential drug interactions to be aware of, but it should be said that most of them are considered relatively minor and not clinically significant.

However, and we'll start with this one, some studies have shown that cranberry can affect the anticoagulant drug Coumadin (warfarin).

Coumadin (Warfarin)

Some studies have found that cranberry can significantly alter Coumadin levels which results in a clinically significant impact. One such study concluded the following:

Cranberry alters the pharmacodynamics of warfarin with the potential to increase its effects significantly. Co-administration of warfarin and cranberry requires careful monitoring.
Br J Pharmacol . 2008 Aug;154(8):1691-700

Other small studies have found similar results, but it is important to note that there certainly is conflicting evidence as some studies have found cranberry has no effects whatsoever.

There is still a lot to learn here as it appears certain individuals may be more susceptible to this interaction than others, or perhaps specific cranberry formulations can affect things.

Regardless, if you take Coumadin, it would be advised to not take cranberry due to uncertain effects, or, at the very least, make sure your doctor is aware.

CYP2C9 Substrates

There are several different liver-metabolizing enzymes, and cranberry has been shown to affect a few of them. One such enzyme is CYP2C9.

Some studies have shown that cranberry can inhibit this enzyme, which could potentially slow the metabolism of some drugs, increasing their risk of side effects.

Some common drugs that are metabolized by CYP2C9 include:

All the drugs on this list, and this list is not all-inclusive, could potentially interact with cranberry.

It is important to note that most scientific sources report that cranberry is likely only a weak inhibitor of CYP2C9, so many of these interactions are thought to be only minor and not clinically significant.

Nevertheless, when it comes to some drugs that have a very small window for error when it comes to dosing, like phenytoin, it may be prudent to skip cranberry as a supplement.

If you do combine cranberry with any of these, be sure to let your doctor know and be on the lookout for any potential side effects.

CYP3A4 Substrates

These potential interactions are very similar to the interactions listed above, only for a different liver metabolizing enzyme. We are now talking about CYP3A4.

There is conflicting evidence, but some studies suggest that cranberry may be a weak inhibitor of the CYP3A4 enzyme, so, drugs that are metabolized by this enzyme may have a higher likelihood of causing side effects due to a decrease in metabolism.

Some common drugs that are metabolized by CYP3A4 include:

Again, this is not a comprehensive list, just some examples of drugs that may interact with cranberry due to the potential effect cranberry have on the CYP3A4 enzyme.

Most of these interactions are considered to be relatively minor, but be sure to keep an eye out for any side effects if you combine cranberry with them.

Final Words

I know I mentioned a lot of drugs in this answer, but in the absence of you providing your medication list, I wanted to just paint a general portrait of what the potential interactions are with cranberry.

You are always more than welcome to reach back out and ask about specific drugs if you'd like.

Thanks so much for contacting us and please do so again anytime.

References

  • Cranberry juice, atorvastatin and back pain, PubMed
  • Cranberry juice suppressed the diclofenac metabolism by human liver microsomes, but not in healthy human subjects, PubMed
  • Flavonoids-potent and versatile biologically active compounds interacting with cytochromes P450, PubMed
  • Cranberry does not affect prothrombin time in male subjects on warfarin, PubMed
  • Pharmacodynamic interaction of warfarin with cranberry but not with garlic in healthy subjects, PubMed
  • Cytochrome P4502C9: an enzyme of major importance in human drug metabolism, PubMed

About the Pharmacist

Dr. Brian Staiger, PharmD

Dr. Brian has been practicing pharmacy for over 13 years and has wide-ranging experiences in many different areas of the profession. From retail, clinical, program development, and administrative responsibilities, he's your knowledgeable and go-to source for all your pharmacy and medication-related questions! Dr. Brian Staiger also has herbalist training and educational certificates in the field of medical ethnobotany. Feel free to send him an email at [email protected]! You can also connect with Dr. Brian Staiger on LinkedIn.

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