Safety Revisions to Norvir (Ritonavir) Tablets, Capsules and Oral Solution Labeling

On December 7, 2011, the Food and Drug Administration approved the following revisions to the Norvir (ritonavir) tablets, capsules and oral solution product labeling:

The Contraindications section was updated to include toxic epidermal necrolysis (TEN) and Stevens-Johnson syndrome.

The Warning and Precautions, Adverse Reactions and Postmarketing Experience sections were updated to include toxic epidermal necrolysis (TEN)

Norvir is a CYP3A4 inhibitor. Initiating treatment with Norvir in patients receiving medications metabolized by CYP3A4 or initiating medications metabolized by CYP3A4 in patients already maintained on Norvir may result in increased plasma concentrations of concomitant medications. Higher plasma concentrations of concomitant medications can result in increased or prolonged therapeutic or adverse effects, potentially leading to severe, life-threatening or fatal events. The potential for drug-drug interactions must be considered prior to and during therapy with Norvir. Review of other medications taken by patients and monitoring of patients for adverse effects is recommended during therapy with Norvir.

Section 7: Drug Interaction was updated to include information regarding the anticancer agents dasatinib and nilotinib and fentanyl. Specifically, the following text was added:

A decrease in the dosage or an adjustment of the dosing interval of nilotinib and dasatinib may be necessary for patients requiring co-administration with strong CYP3A inhibitors such as Norvir. Please refer to the nilotinib and dasatinib prescribing information for dosing instructions.

Concentrations of fentanyl are expected to increase. Careful monitoring of therapeutic and adverse effects (including potentially fatal respiratory depression) is recommended when fentanyl is concomitantly administered with Norvir.

The updated label is available here.