The Medication Piece of the Puzzle
When you are trying to understand and manage your body’s histamine reactions, it's common to focus on the most visible factors, like the food on your plate or your daily stress levels. You might be keeping a detailed food diary and carefully managing your Histamine Bucket, but still find yourself experiencing unexplained flare-ups. This is obviously a frustrating place to find yourself.
There is a growing body of evidence indicating that some common and often essential medications can interfere with the activity of your body’s primary enzyme for breaking down dietary histamine: diamine oxidase, or DAO. We're going to explore that connection in this article.
Before we get started, it is crucial that under no circumstances should you stop or change the dose of any prescribed medication without consulting the doctor who prescribed it. This article is designed to empower you with clear, evidence-based information, that you can discuss it with your healthcare professional. By understanding potential connections between your medication and your histamine reactions, you can see your wider health picture in a more holistic way and look for alternate strategies towards beating your reactions.
What Does it Mean to “Block” an Enzyme?
Let's begin by defining what we mean by a ‘DAO blocker’. Your DAO enzyme has a very specific job, which is to break down histamine that you consume from food and drink. For a deeper look at this process you can read our article on how diamine oxidase works.
Enzymes work in your body a little bit like a 'lock and key'. Each enzyme (the lock) has a unique shape, and the molecule it works on, which in this case is histamine (the key), fits perfectly into it. An ‘inhibitor’ or ‘blocker’ is another substance that can also fit into the same lock. By occupying the same space it prevents the histamine from getting in. This means the enzyme cannot do its job as effectively, and some of the histamine passes by your DAO and into your bloodstream, causing your histamine bucket to fill up faster.
While it's a completely different reaction, this is also how caffeine works in your body, blocking your adenosine receptors and preventing you from feeling tired. The human body really is a fascinating place!
Common Medications That May Influence DAO Activity
It is important to remember that research in this area is ongoing, and the effect can vary significantly from person to person. However, studies have suggested that several classes of medication may inhibit DAO activity.
- Certain Painkillers: Some non-steroidal anti-inflammatory drugs (NSAIDs), such as acetylsalicylic acid and indomethacin, have been noted for their potential to inhibit DAO
- Some Antidepressants: Certain types of antidepressants, including citalopram and amitriptyline, have been identified as potential DAO inhibitors
- Certain Diuretics: These medications such as amiloride, which are used to manage blood pressure, have also been researched for their effect on DAO
- Mucolytics: These are medicines used to help clear mucus from the airways. Acetylcysteine (ACC) is one that has been shown to have an inhibitory effect on the DAO enzyme
- Some Antibiotics: Certain antibiotics like clavulanic acid (often combined with amoxicillin), have been linked to reduced DAO activity
- Other Medications: The list of potential inhibitors is long and includes some muscle relaxants, medications for heart conditions, diabetes medication and treatments for tuberculosis
Again, we have to stress that seeing a medication on this list does not mean it is definitely causing a problem for you. It simply represents a potential connection that is worth being aware of and discussing with your healthcare team.
What is the Next Step?
Discovering that a necessary medication might be contributing to your reactions can feel unsettling. The most important thing is how you use this information and remember that it is a tool for further inquiry, and not a call for action.
Under no circumstances should you stop or change the dose of any prescribed medication without consulting the doctor who prescribed it. The consequences of doing so can be very serious. Many of the medications listed above are designed to treat medical conditions with far more serious consequences than DAO deficiency.
Instead, we encourage a proactive and collaborative approach:
- Gather Your Data: Continue to keep a detailed diary of your food, activities, and any reactions. Make a special note of when you take your medications to provide a clear picture for your healthcare provider
- Talk to Your Doctor: Schedule an appointment with your GP or the specialist who manages your prescription. You can explain that you are trying to understand histamine intolerance and have read that some medications can influence DAO activity
- Ask Informed Questions: You could ask, “Is it possible that my medication could be contributing to these symptoms? Are there any alternative medications for my condition that are known to have less impact on the DAO enzyme?”
- Work with a Specialist: A registered dietitian specialising in histamine intolerance can be an invaluable ally. They can help you navigate your diet and work alongside your doctor to create a comprehensive management plan, which may include DAO supplementation if your medications are inhibiting your natural enzyme activity. You can find a list of trusted practitioners on our Practitioners page
Understanding the full picture of your health is an ongoing journey, and understanding the potential role of medications is another step towards feeling more in control and having more productive conversations with the professionals who support you.
This article is for informational purposes only and does not constitute medical advice. Please consult a qualified healthcare professional for advice specific to your situation.