etopophos and norvir-soft-gelatin Interactions

You searched for interactions between:

• etopophos
• norvir-soft-gelatin (ritonavir)

Interaction(s) found:

ritonavir and etoposide phosphate (Moderate Drug-Drug)

MONITOR: Coadministration with ritonavir may increase the plasma concentrations of drugs that are substrates of the CYP450 3A4 isoenzyme. The mechanism is decreased clearance due to inhibition of CYP450 3A4 activity by ritonavir. The area under the plasma concentration-time curve (AUC) of some coadministered drugs has been reported to increase by 3-fold or more.

MANAGEMENT: Caution is advised if ritonavir must be used concurrently with medications that undergo metabolism by CYP450 3A4, particularly those with a narrow therapeutic range. Dosage adjustments as well as clinical and laboratory monitoring may be appropriate for some drugs whenever ritonavir is added to or withdrawn from therapy.