Answer
Ketoconazole inhibits CYP3A4, the main enzyme responsible for budesonide metabolism, and can increase systemic exposure to oral budesonide several times, so the combination should be avoided.
Sources for this answer
- Entocort CR 3mg CapsulesTillotts Pharma UK Limited · emc · SmPC §4.5 Interaction with other medicinal products · Version 28Document updated
Sources checked