Metastatic Prostate Cancer Drug Warnings & Dosage

What drugs interact with Yonsa?

Drugs That Inhibit Of Induce CYP3A4 Enzymes

Based on in vitro data, Yonsa is a substrate of CYP3A4.

In a dedicated drug interaction trial, co-administration of rifampin, a
strong CYP3A4 inducer, decreased exposure of abiraterone by 55%. Avoid
concomitant strong CYP3A4 inducers during Yonsa treatment. If a strong CYP3A4
inducer must be co-administered, increase the Yonsa dosing frequency.

In a dedicated drug interaction trial, co-administration of ketoconazole, a
strong inhibitor of CYP3A4, had no clinically meaningful effect on the
pharmacokinetics of abiraterone.

Effects Of Abiraterone On Drug Metabolizing Enzymes

Abiraterone is an inhibitor of the hepatic drug-metabolizing enzymes CYP2D6
and CYP2C8. In a CYP2D6 drug-drug interaction trial, the Cmax and AUC of
dextromethorphan (CYP2D6 substrate) were increased 2.8and 2.9-fold,
respectively, when dextromethorphan was given with an abiraterone acetate dose
equivalent to Yonsa 500 mg daily and a different corticosteroid twice daily.
Avoid coadministration of abiraterone acetate with substrates of CYP2D6 with a
narrow therapeutic index (e.g., thioridazine). If alternative treatments cannot
be used, exercise caution and consider a dose reduction of the concomitant
CYP2D6 substrate drug.

In a CYP2C8 drug-drug interaction trial in healthy subjects, the AUC of
pioglitazone (CYP2C8 substrate) was increased by 46% when pioglitazone was given
together with an abiraterone acetate single dose equivalent to Yonsa 500 mg.
Therefore, patients should be monitored closely for signs of toxicity related to
a CYP2C8 substrate with a narrow therapeutic index if used concomitantly with
abiraterone acetate.