Liverpool COVID-19 Interactions

Potential Interaction

Nirmatrelvir/ritonavir (5 days)

Lopinavir/ritonavir

Quality of Evidence: Very Low

Summary:

Coadministration has not been studied. Patients on ritonavir- or cobicistat- containing regimens should continue their treatment with no dosage modification. Patients should be informed about the potential occurrence of adverse effects (i.e. gastro-intestinal due to the higher dose of ritonavir).

Description:

Concomitant therapy with ritonavir-containing regimen - no dose adjustment is needed; the dose of Paxlovid is 300 mg/100 mg twice daily for 5 days. Patients diagnosed with human immunodeficiency virus (HIV) who are receiving ritonavir-containing regimen should continue their treatment as indicated.

Paxlovid GB Summary of Product Characteristics, Pfizer Ltd, December 2024.

No dose adjustment of Paxlovid is needed. Patients diagnosed with human immunodeficiency virus (HIV) infection who are receiving a ritonavir-containing regimen should continue their treatment as indicated.

Paxlovid EU Summary of Product Characteristics, Pfizer, February 2025.

Patients on ritonavir-containing HIV regimens should continue their treatment as indicated. Coadministration may increase lopinavir concentrations. For further information, refer to the lopinavir/ritonavir prescribing information. Monitor for increased Paxlovid or protease inhibitor adverse events.

Paxlovid US Prescribing Information, Pfizer Inc, February 2025.