Supplements and Azathioprine.
Azathioprine, sold under the brand name Imuran, is a thiopurine immunosuppressant.
Azathioprine is a thiopurine immunosuppressant. It is used in inflammatory bowel disease, autoimmune hepatitis, and some leukaemias. UK prescribing centres on azathioprine and mercaptopurine. The class requires TPMT (thiopurine methyltransferase) genotype or activity testing before starting in most UK centres, because low TPMT activity drives severe myelosuppression at standard doses. The supplement surface includes the interaction with allopurinol. Allopurinol can be given alongside but requires substantial thiopurine dose reduction. It also includes any supplement with significant bone marrow effect. Folate supplementation is sometimes added given the antimetabolite mechanism. The herpes virus and JC virus reactivation signal matters for any patient on sustained thiopurine therapy. Immune-stimulating supplements warrant care during active treatment. Liver function monitoring is routine.
Below are the 3 documented pairs we have explicitly assessed against Azathioprine in the Distil database: 3 amber. The pairs cluster around 1 mechanism: Immunosuppression caution. Every call is cited to either a clinical reference (PMID) or the British National Formulary. Anything not on this list is either still to be assessed or beyond our database scope. The checker beneath surfaces assessments by supplement, and the missing-item form at the bottom of the page routes any uncatalogued supplement into our next curation pass.
Documented interactions
Immunosuppression caution
If you take a medicine that suppresses your immune system, check with your specialist before starting any probiotic. The pasteurised (non-living) form used here lowers the usual concern, but immune data are incomplete, so a quick word with your team is the safe route.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Bifidobacterium longum 1714 is a live bacterium, and for most people it is safe. But azathioprine dampens the immune system, often for an autoimmune condition or after a transplant, and in people whose defences are significantly weakened there have been rare cases of a probiotic organism getting into the bloodstream and causing an infection. If you take azathioprine, it is sensible to check with your specialist before starting this strain, and to avoid it if you are seriously unwell in hospital or have a central line or drip.
Probiotics are live bacteria or yeast, and for most people they are safe. But azathioprine dampens the immune system, often for an autoimmune condition or after a transplant, and in people whose defences are significantly weakened there have been rare cases of the probiotic organism getting into the bloodstream and causing an infection. If you take azathioprine, it is sensible to check with your specialist before starting a probiotic, and to avoid them if you are seriously unwell in hospital or have a central line or drip.
What this list does not say. Pairs not flagged here are not implicitly safe. They are either not yet in our database, or fall outside our inclusion scope (food-supplement interactions only; for drug-drug interactions, the BNF is authoritative). Use the checker below to surface any supplement, and submit a missing item if you take something we have not catalogued.
How we grade severity, choose what's in scope, and what we exclude.
Every call on this page is reasoned. We publish the full rubric for severity tiers, the medication inclusion logic, the evidence grades we accept, and what we deliberately leave out. About three thousand words. Worth reading once if you use this tool more than occasionally.
Read the full methodologyWant this checked across everything you take?
This page checks the pairs you enter. The personalised Distil report goes further:
- the same graded, cited interaction check across your whole stack, not just the pairs you thought to type in
- where your current routine may be leaving you short of your goals
- the evidence-backed compounds worth adding, and the ones worth dropping
It's a paid report: £79, or £49 for the first 25 customers. The interactions check is one section of it, and you can read a real one in full before you buy.
See a real sample reportSomething missing?
If a supplement or medication you take isn't in our autocomplete, tell us. We go through what people flag every week and add what's missing.