Is Saccharomyces boulardii Safe with Itraconazole?
Free · No account · based on published sources including NIH ODS, FDA drug labels, and peer-reviewed literature
Do NOT use Saccharomyces boulardii with itraconazole or any azole antifungal. Switch to a bacterial-based probiotic (e.g., Lactobacillus or Bifidobacterium strains) during the course of antifungal treatment and for at least 1 week after completing therapy. Inform all healthcare providers of all supplements being taken.
Why this interaction occurs
Itraconazole inhibits cytochrome P450-dependent lanosterol 14-alpha-demethylase in fungi, blocking ergosterol synthesis and causing fungal cell death. Saccharomyces boulardii, being a viable yeast organism, is directly susceptible to this mechanism of action. Co-administration results in complete destruction of the probiotic yeast, making the supplement biologically inert. This is a well-characterized pharmacodynamic incompatibility.
Evidence
Evidence level: strong.
Data source
PubMed: PMID 27250926
Reported safety data
The FDA’s adverse event reporting system (FAERS) has received 9,352 reports mentioning Itraconazole. This reflects reported cases involving the medication in general — not confirmed causation, and not specific to the Itraconazole + supplement combination on this page.
FAERS reports are voluntary and cannot prove that a drug caused an event. Do not use report counts to assess the safety of this specific drug-supplement pair.
Frequently asked questions
Related interactions
All Saccharomyces boulardii interactions → · All Itraconazole interactions →
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Educational only — not medical advice.
Always confirm with your doctor or pharmacist.