Interactions : אינטראקציות

4.5   Interaction with other medicinal products and other forms of interaction
In vitro and pharmacogenomic studies indicate that belzutifan is metabolised by UGT2B17 and by CYP2C19.
Effects of belzutifan on other medicinal products

Coadministration of Welireg with CYP3A4 substrates, including hormonal contraceptives, decreases concentrations of CYP3A substrates (see sections 5.1 and 5.2), which may reduce the efficacy of these substrates. The magnitude of this reduction may be more pronounced in patients who are dual UGT2B17 and CYP2C19 poor metabolisers (see section 5.1).

Avoid coadministration of belzutifan with sensitive CYP3A4 substrates, for which minimal decrease in concentration may lead to therapeutic failures of the substrate. If coadministration cannot be avoided, increase the sensitive CYP3A4 substrate dosage in accordance with its summary of product characteristics.

Coadministration of WELIREG with hormonal contraceptives may lead to contraceptive failure or an increase in breakthrough bleeding.

Effects of other medicinal products on belzutifan
Co-administration of belzutifan with inhibitors of UGT2B17 or CYP2C19 increases plasma exposures of belzutifan, which may increase the incidence and severity of adverse reactions of belzutifan.
Monitor for anaemia and hypoxia and reduce the dosage of belzutifan as recommended.