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nirmatrelvir + ritonavir

Paxlovid · ATC code J05AE30

Also known as: Nirmatrelvir / Ritonavir

Key facts
Active substance
nirmatrelvir + ritonavir (INN: nirmatrelvir / ritonavir)
Drug class
Direct acting antiviral
ATC code
J05AE30
Authorisation
centrally authorised across the EU (EMA)
Dosage forms
Paxlovid 150 mg + 100 mg film-coated tablets
Marketing authorisation holder
Pfizer Europe MA EEIG
Information as of
2026-10-27

Key facts

Nirmatrelvir + ritonavir (Paxlovid) is an antiviral combination: nirmatrelvir inhibits the SARS-CoV-2 protease and ritonavir, a CYP3A inhibitor, boosts its levels. It is used to treat COVID-19 in patients at risk of severe disease.

What it is used for

  • COVID-19 in adults and children 6 years and older weighing at least 20 kg who do not need supplemental oxygen and are at increased risk of progressing to severe COVID-19

Dosing

  • Adults and children 6 years and older weighing ≥40 kg: 300 mg nirmatrelvir (two 150 mg tablets) with 100 mg ritonavir every 12 hours for 5 days
  • Children 6 years and older weighing ≥20 to <40 kg: 150 mg nirmatrelvir with 100 mg ritonavir every 12 hours for 5 days
  • Start as soon as possible after diagnosis and within 5 days of symptom onset
  • Moderate or severe renal impairment: reduced dose as given in the full text
  • Mild or moderate hepatic impairment: no adjustment; severe hepatic impairment (Child-Pugh C): not to be used

Contraindications

  • Hypersensitivity to the active substances or excipients
  • Medicines highly dependent on CYP3A where raised levels are life-threatening (e.g. alfuzosin, ranolazine, dronedarone, colchicine, lurasidone, quetiapine, silodosin, ergotamine)
  • Strong CYP3A inducers (list in the full text)

Important warnings

  • High risk of serious adverse reactions from drug interactions; review all concomitant medicines
  • Paxlovid increases concentrations of CYP3A substrates
  • Calcineurin and mTOR inhibitors: only with multidisciplinary consultation and close level monitoring

Side effects

  • Common: dysgeusia, diarrhoea, headache, vomiting, nausea
  • Uncommon: hypersensitivity, hypertension, abdominal pain, rash
  • Rare: anaphylaxis, toxic epidermal necrolysis

Interactions

  • CYP3A inducers may reduce the effect of Paxlovid
  • CYP3A4 inhibitors may increase nirmatrelvir and ritonavir levels
  • Ritonavir may reduce the efficacy of combined hormonal contraceptives

Pregnancy and breastfeeding

  • Limited data; avoid pregnancy during treatment and for 7 days after as a precaution; with hormonal contraceptives add a barrier method
  • Breast-feeding should be discontinued during treatment and for 48 hours after

Summary of the official product information, written with AI (Claude, Anthropic) on 2026-10-28. Every number was checked automatically against the original text. Not reviewed by a physician – the full official text is authoritative.

Full official text →

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For patients

Package leaflet, verbatim

Package leaflet for patients →

Authorisation and brand names by country

Medicines with exactly this active-substance composition, as listed in the national registers – alphabetical and without ranking. Whether a product is currently available is not shown here.

EU – centrally authorised (all member states)

  • PaxlovidPfizer Europe MA EEIG · EMEA/H/C/005973

Source: European Medicines Agency (EMA), product information

Turkey

  • PaxlovıdPFİZER PFE İLAÇLARI A.Ş. · 1 register entry

Source: TİTCK – Ruhsatlı Beşeri Tıbbi Ürünler Listesi, as of 2026-10-16

Medelix receives no money from pharmaceutical companies. Brand names are listed alphabetically and without ranking.

Other substances in the same group

Another question about this substance?

Medelix answers clinical questions from guidelines, studies and product information – every claim with its source.

Sources

  1. European Medicines Agency. Paxlovid – EPAR, Product Information (OF THE TEXT Detailed information on this medicinal product i). 2026-10-27. https://www.ema.europa.eu/en/documents/product-information/paxlovid-epar-product-information_en.pdf
  2. TİTCK – Ruhsatlı Beşeri Tıbbi Ürünler Listesi, 2026-10-16. https://www.titck.gov.tr/dinamikmodul/85
  3. Wikidata (CC0): ATC J05AE.

Editorial: Medelix editorial team · last updated 2026-10-27 · How these pages are made · Report an error

Source: European Medicines Agency (EMA), product information. Not advertising, not a treatment recommendation. For questions about your own treatment, ask your doctor or pharmacist.