Major
Budesonide × Ketoconazole
Inhaled corticosteroids (ICS)×Systemic antimycotics. Imidazole derivatives
Mechanism
Ketoconazole strongly blocks CYP3A4 – the main budesonide metabolic route. Systemic budesonide exposure (oral or inhaled) rises 6- to 12-fold. High Cushing's syndrome risk with prolonged combination.
Symptoms
Moon face, central obesity, abdominal striae, hypertension, hyperglycaemia. With prolonged combination and abrupt withdrawal: adrenal insufficiency risk.
Management
The combination is not prescribed. Alternative antifungals: terbinafine for dermatophytosis or echinocandins for systemic mycoses. Alternative inhaled corticosteroid: fluticasone/mometasone (less CYP3A4-dependent).
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.
Sources
- FDA: Nizoral (ketoconazole) prescribing information (2014)
- EMA: Huperzine A is not authorised as a medicinal product in the EU (2024)– EMA – no centralised authorisation for huperzine A