Please consult the SmPC for full details on dosing and contraindications before any prescribing decisions are made.

Renal adjustments

No dose adjustment of PAXLOVID is required for patients with mild renal impairment (eFGR ≥60 to <90 mL/min, CKD Stage 2).

For moderate renal impairment (eGFR ≥30 to <60 mL/min, CKD Stages 3A & 3B), the dose of PAXLOVID should be reduced to 1 nirmatrelvir tablet and 1 ritonavir tablet, twice daily for 5 consecutive days. We recommend cutting out the no-longer needed additional nirmatrelvir tablets from the blister pack prior to dispensing the prescription. The remaining tablets of nirmatrelvir should be disposed of in accordance with local requirements. We are recommending this approach to prevent patient confusion.

PAXLOVID is contraindicated for patients with renal failure and severe renal impairment (eGFR <30 mL/min, CKD Stages 4 & 5).

Hepatic Adjustments

No dose adjustment of PAXLOVID is required for patients with either mild (Child-Pugh Class A) or moderate (Child-Pugh Class B) hepatic impairment.

PAXLOVID is contraindicated in patients with severe hepatic impairment (Child-Pugh Class C).

Hepatic transaminase elevations, clinical hepatitis and jaundice have occurred in patients receiving ritonavir. Therefore, caution should be exercised when administering Paxlovid to patients with pre-existing liver diseases, liver enzyme abnormalities or hepatitis.

Additional information

Concomitant therapy with ritonavir or cobicistat
No dose adjustment of Paxlovid is needed. Patients diagnosed with human immunodeficiency virus or hepatitis C virus infection receiving ritonavir- or cobicistat-containing regimen should continue their treatment as indicated.

Coadministration with calcineurin inhibitors and mTOR inhibitors
Consultation of a multidisciplinary group (e.g., involving physicians, specialists in immunosuppressive therapy, and/or specialists in clinical pharmacology) is required to handle the complexity of this coadministration by closely and regularly monitoring immunosuppressant blood concentrations and adjusting the dose of the immunosuppressant in accordance with the latest guidelines (refer to SmPC section 4.5).

Excipients
Nirmatrelvir tablets contain lactose. Patients with rare hereditary problems of galactose intolerance, total lactase deficiency or glucose-galactose malabsorption should not take this medicine.

Nirmatrelvir and ritonavir tablets each contain less than 1 mmol sodium (23 mg) per dose, that is to say essentially 'sodium-free'.

Hypersensitivity reactions
Anaphylaxis, hypersensitivity reactions, and serious skin reactions (including toxic epidermal necrolysis and Stevens-Johnson syndrome) have been reported with Paxlovid (see SmPC section 4.8). If signs and symptoms of a clinically significant hypersensitivity reaction or anaphylaxis occur, immediately discontinue Paxlovid and initiate appropriate medications and/or supportive care.

Elderly population
No dose adjustment is recommended for elderly patients.

Paediatric population
The safety and efficacy of Paxlovid in patients below 18 years of age have not been established. No data are available.

HIV resistance
As nirmatrelvir is coadministered with ritonavir, there may be a risk of HIV-1 developing resistance to HIV protease inhibitors in individuals with uncontrolled or undiagnosed HIV-1 infection.

Pregnancy
There are limited data from the use of Paxlovid in pregnant women. Paxlovid should be used during pregnancy only if the potential benefits outweigh the potential risks for the mother and the foetus.

Women of childbearing potential
There are limited human data on the use of Paxlovid during pregnancy to inform the drug-associated risk of adverse developmental outcomes. Women of childbearing potential should avoid becoming pregnant during treatment with Paxlovid.

Contraception in males and females
Use of ritonavir may reduce the efficacy of combined hormonal contraceptives. Patients using combined hormonal contraceptives should be advised to use an effective alternative contraceptive method or an additional barrier method of contraception during treatment and until after one complete menstrual cycle after stopping Paxlovid.

Breast feeding
Paxlovid is excreted in breastmilk in small amounts. There are no data on the effects of nirmatrelvir or ritonavir on the breast-fed newborn/infant or on breast milk production. A risk to the newborn/infant cannot be excluded. Breast-feeding should be discontinued during treatment with Paxlovid and for 48 hours after the last dose of Paxlovid.