Budenofalk Drug Interactions

Pharmacodynamic interactions: Cardiac glycosides: The action of the glycoside can be potentiated by potassium deficiency.
Saluretics: Potassium excretion can be enhanced.
Pharmacokinetic interactions: Cytochrome P450 3A (CYP3A): CYP3A inhibitors Co-treatment with CYP3A inhibitors, including cobicistat-containing products, is expected to increase the risk of systemic side-effects. The combination should be avoided unless the benefit outweighs the increased risk of systemic corticosteroid side-effects, in which case patients should be monitored for systemic corticosteroid side-effects.
Ketoconazole 200 mg once daily p.o. increased the plasma concentrations of budesonide (3 mg single dose) approximately 6-fold during concomitant administration. When ketoconazole was administered 12 hours after budesonide, the concentrations increased approximately 3-fold. As there are not enough data to give dose recommendations, the combination should be avoided.
Other potent inhibitors of CYP3A4 such as ritonavir, itraconazole, clarithromycin, and grapefruit juice are also likely to cause a marked increase of the plasma concentrations of budesonide. Therefore concomitant intake of budesonide should be avoided.
The effect of the corticosteroid can be potentiated.
CYP3A inductors, such as carbamazepine and rifampicin may reduce the systemic and also the local exposure of budesonide at the intestinal mucosa. The budesonide dose may require adjustment.
CYP3A substrates, such as ethinylestradiol compete for metabolism with budesonide. If the affinity of the competing substance for CYP3A is stronger, this may lead to increased budesonide plasma concentrations. If budesonide binds stronger to CYP3A, plasma levels of the competing substance may be increased. In such cases, the dose of budesonide or the competing substance may need adjustment.
Elevated plasma concentrations and enhanced effects of glucocorticosteroids have been reported in women also receiving estrogens or oral contraceptives. This interaction has not been observed with oral low dose combination contraceptives.
Concurrent administration of cimetidine and budesonide can result in a small, but clinically insignificant increase in budesonide plasma levels. Concurrent administration of omeprazole has no effect on the pharmacokinetics of budesonide.
Potential interactions with steroid-binding synthetic resins such as colestyramine and with antacids cannot be ruled out. If given at the same time as Budenofalk 3 mg, such interactions could result in a reduction in the effect of budesonide. Therefore these preparations should be taken at least 2 hours apart.
Because adrenal function may be suppressed by treatment with budesonide, an ACTH stimulation test for diagnosing pituitary insufficiency might show false results (low values).