Histamine Intolerance: Medications to Avoid

Histamine Intolerance: Medications to Avoid

Can’t get a grip on your histamine intolerance symptoms? Take a look at these common medications as a potential cause…

In today’s world, it’s not uncommon to find someone that is taking some or other medication; prescribed or over-the-counter!

What, with all we have to deal with from the troubles of the world and the toll it takes on our mental health, to the foods we eat that may not be that good for us because of the way they are made, and the genes we have been born with that we didn’t really have a say in getting.

It all affects our health in some way, and so it’s not surprising to find many people simply needing to take a daily antidepressant, statin, blood pressure medication or pain killers; or a combination of all of the above just to get by.

The trouble is, when you’re living with histamine intolerance, you may not be aware of the effects that these medications are having on your condition. And you could be chalking your flare ups to other environmental exposures or even food, when really, it’s the medication you’re taking that could be having a sneaky and significant impact. 

Now, let’s take a look at the most common medications and their effects on histamine intolerance. 

Histamine intolerance: medications to avoid list

Before we get into the specifics of the medications that may cause your histamine intolerance symptoms to continue spinning out of control, it’s essential that you know you should never stop any of the medications you are taking without the explicit instruction of your medical doctor to do so, even if this article does show you that what you’re taking may be compounding your histamine intolerance. 

Regarding prescription medications or any other supplement or medication recommended by a healthcare practitioner, it is essential that they approve for you to stop or switch these.

The information we are providing to you is so that you can now recognise what could be keeping you in a flare up, which now gives you the power to speak to your doctor or treating physician to provide you with alternatives.

So, instead of continuing to cut out foods or other environmental factors that you think might be causing your symptoms, you can get to the root cause of your flare ups and do something about it! 

Ok, so back to medications to avoid with histamine intolerance....

First up are seven categories of medications we want to present as having an effect on histamine intolerance, but specifically because they affect the activity of diamine oxidase, or DAO. And seeing as many of you may histamine intolerant individuals have a deficiency of DAO enzymes or are using DAO enzyme supplements to feel better, it's a good place to start, as these medications are actually very common!


DAO enzyme inhibitors: 

  1. Painkillers like ibuprofen and aspirin which are also known as NSAIDs; codeine and morphine are opioid painkillers associated with heightened symptoms 
  2. Heart arrhythmia medications, especially those ending in -olol 
  3. Antihistamines such as benadryl as well as histamine H2 blockers like zantac (this one is surprising and quite ironic, isn't it!)
  4. Antidepressants like prozac, zoloft and cymbalta, as well as antipsychotics 
  5. Metformin for diabetes 
  6. Immune modulating medications such as plaquenil and humira 
  7. Antihypertensives that treat high blood pressure 

I bet you raised an eyebrow when you saw number 3 on this list. I don’t blame you!

The trouble with antihistamines and histamine blockers though, is that while they switch off the receptors for histamine release, they do so at the expense of DAO production.

So, even though your body is in a sense not being told to release histamine from your mast cells, if you’re still having histamine being produced by your gut bacteria, or it’s coming into your body from food, you’re still not going to have the capacity to break it down effectively because your DAO enzyme levels are low due to being suppressed by the medication you’re taking; one that’s supposed to be helping you!

This issue is why I work with an all-natural antihistamine that stabilizes mast cells without reducing the impact on DAO enzymes. For those that have a genetic or other deficiency in DAO production, they may also choose to use DAO enzyme supplements in combination with these natural antihistamines.

The other medications to be aware of if you're histamine intolerant include:

  • Muscle relaxants like voltaren 
  • Medications that treat digestive issues such as nausea and reflux 
  • Those that open up the airways or treat lung disorders 
  • Antibiotics, especially those under the beta-lactam category 
  • Diuretics
  • Malaria treatments and preventative drugs
  • Tuberculosis treatment regimes
  • Contrast media for radiographs (i.e., dyes used to emphasize body structures when taking X-rays like in CT scans or angiography)  
  • General anesthesia 

Studies have shown that when sensitive individuals take these medications, it’s common to experience hives, urticaria or itching, and other symptoms related to mild allergies. In some rare cases, individuals may even experience symptoms of anaphylaxis, such as difficulty breathing and facial or throat swelling, especially when they’re extremely sensitive and histamine levels are far higher than usual (1). 

If it is indeed the medication contributing to your symptoms, it’s likely that you’re experiencing more ongoing and general symptoms of histamine intolerance, which are sure to decrease once you switch to another type of medication.

So take note of symptoms such as diarrhea, headaches, bloating, flushing, itching (across the body as well as eyes and nose), heart palpitations, dizziness, nausea, pain in the abdomen and sinus or nasal congestion every time you take your meds.

Also note that although histamine intolerance can mimic allergy symptoms, it is not a true allergy. True allergies will come on quickly, whereas intolerances can have a delayed onset. So, just because you're not flaring up immediately after your medication, it doesn't necessarily mean there isn't a link between histamine intolerance symptoms and your medication.

Supplements to avoid with histamine intolerance

Note that when it comes to supplements to avoid with histamine intolerance, depending on if it was your choice to take them or if it was directed by a healthcare practitioner, you may have the option to stop if the former applies.

There are many supplements to avoid with histamine intolerance due to active ingredients or additives, which makes it quite a difficult topic to discuss compared to medications.

The reason for that is because you can have two supplements that have the same active ingredient but depending on the sourcing and additives, one can be higher in histamine and one can be lower in histamine.

Then, there are other supplements that simply shouldn't be taken, like most probiotics which contain histamine producing bacteria. You can check out this list of high histamine probiotics. If you're taking these, it's best to swap probiotics to a low histamine version.

This is why I created the low histamine supplement brand, Unitee. The goal was to ensure all supplements carried are suitable for individuals with histamine intolerance, so there doesn't have to be any guesswork or "weird reactions" from using the same supplement from different brands.

Once again, if you have chosen on your own to take a certain supplement without the guidance of a healthcare practitioner, this is more within your own control and decision whether to stop or continue. 

However, if your healthcare practitioner has recommended a certain supplement and you are concerned about the histamine content it carries, it is still important to speak to that practitioner before stopping or swapping your routine around, even if it a known supplement to avoid with histamine intolerance.

Navigating histamine intolerance when you need these medications

If you’re taking any of these medications on a regular basis the good news is that there are so many alternatives available to you. And if they are a cause of your uncontrolled histamine intolerance symptoms, it’s best to get your doctor to help you to switch if that is indeed possible for your particular case.

I mean, imagine you do, and you’re able to manage your symptoms better, allowing you to eat more foods and actually provide your body with the nutritional support it needs to help you to overcome your symptoms completely.

In the meantime, while you navigate changing your medication, try to keep your histamine levels at the lowest that you have the capacity to. To help, we have a complementary comprehensive food guide to histamine intolerance to share with you. You can click below to get the low histamine diet guide directly to your inbox.

Get the low histamine diet!


Additionally, you may want to consider taking a natural antihistamine or DAO supplement alongside your meals, as well as a low-histamine probiotic to reduce the histamines being produced by your gut.

Now you have another piece of the puzzle that creates the picture of the underlying cause of why you have the condition in the first place. Another step closer towards living a life free from the debilitating symptoms that histamine intolerance causes.  


  1. Bonadonna, P., & Lombardo, C. (2014). Drug Allergy in Mastocytosis. Immunology and Allergy Clinics of North America, 34(2), 397–405.  
Author Photo

Anita Tee

My name is Anita Tee. I'm a nutritional scientist who specializes in histamine intolerance. I hold a Master of Science in Personalized Nutrition and a Bachelor of Science in Human Biology and Psychology.For the past ten years, I have used my experience in nutritional and medical health sciences to create a scientifically backed, natural approach to healthcare that relies 100% on evidence-based research.As I previously suffered from - and overcame - histamine intolerance, my focus is to increase recognition and expand the available resources and protocols available for resolving this particular disorder. To date, I have helped over 4,000 individuals fully resolve or better manage their histamine intolerance symptoms.

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