Interactions : אינטראקציות

4.5   Interaction with other medicinal products and other forms of interaction

Interaction with other medicinal products:
Combination with phenobarbital, rifampin, phenytoin or ephedrine may increase the metabolism of corticosteroids, resulting in a decrease in therapeutic effect.

Patients who simultaneously receive a corticosteroid and an estrogen must be monitored for excessive corticosteroid effects.

The simultaneous administration of corticosteroids and cardiac glycosides may increase the risk of arrhythmias or digitalis toxicity related to hypokalemia. Often, patients using cardiac glycosides also take diuretics which induce potassium depletion; in this case, it is essential to conduct potassium level determinations. Corticosteroids may aggravate the potassium depletion caused by amphotericin B. In all patients taking one of these medication combinations, serum electrolytes, particularly serum potassium, should be closely monitored.

The simultaneous use of corticosteroids and coumarin-type anticoagulants may increase or decrease the effects of anticoagulants, which may require a dosage adjustment.

Corticosteroids may decrease the concentration of blood levels of salicylates. In hypoprothrombinemia, caution should be observed when using acetylsalicylic acid during corticotherapy.

The combination with non-steroidal anti-inflammatories or alcohol can lead to an increased risk of developing a gastrointestinal ulcer or worsening of an existing ulcer.

In diabetics, it is sometimes necessary to adjust the dose of oral antidiabetic agents or insulin, given the intrinsic hyperglycemic effect of glucocorticoids.

Combination with somatotropin may inhibit the response to this hormone. Betamethasone doses greater than 300-450 µg (0.3 to 0.45 mg) per m2 of body surface area per day should be avoided during administration of somatotropin.

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.

Other forms of interactions
Interactions with laboratory tests
Corticosteroids may influence the nitro blue tetrazolium reduction test and produce false negative results.