Generic name: nirmatrelvir and ritonavir
Drug class: Antiviral combinations
Dosage form: tablets, co-packaged for oral use
Availability: Prescription only
Pregnancy & Lactation: Risk data available
Brand names: Nirmatrelvir (monograph), Nirmatrelvir and ritonavir
What is Paxlovid?
Paxlovid (nirmatrelvir tablets co-packaged with ritonavir tablets) is an FDA-approved medicine to treat adults with mild-to-moderate COVID-19 and who are at high risk for progression to severe COVID-19, including hospitalization or death.
Paxlovid is available under an Emergency Use Authorisation (EUA) to treat patients 12 to 18 years old for mild-to-moderate COVID-19 who are at high risk for progression to severe COVID-19, including hospitalization or death.
Paxlovid should be taken as soon as possible after diagnosis of COVID-19. It is taken to decrease the number and severity of symptoms or avoid severe illness, which may lead to hospitalization or death.
Paxlovid may be prescribed for an individual patient by physicians, advanced practice registered nurses, and physician assistants that are licensed or authorized under state law to prescribe drugs. It may also be prescribed for an individual patient by a state-licensed pharmacist under specific conditions.
Paxlovid is not approved or authorized for use as a pre-exposure or post-exposure prophylaxis for the prevention of COVID-19.
How should I take Paxlovid
Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.
Take nirmatrelvir together with ritonavir (two tablets of nirmatrelvir and one tablet of ritonavir) twice a day for 5 consecutive days.
If you have kidney disease, talk to your healthcare provider. You may need a different dose.
Take Paxlovid as soon as possible after diagnosis of COVID-19 and within 5 days of when symptoms first appear.
You may take Paxlovid with or without food.
Swallow the tablets whole and do not crush, chew, or break them.
You may need frequent blood tests to check your liver function.
If you are taking a ritonavir- or cobicistat-containing medicine to treat hepatitis C or Human Immunodeficiency Virus (HIV), you should continue to take your medicine as prescribed by your healthcare provider.
Talk to your healthcare provider if you do not feel better or if you feel worse after 5 days.
Dosing information
Usual Paxlovid Adult Dose for COVID-19 (FDA-approved)
Nirmatrelvir: 300 mg orally twice a day
Ritonavir: 100 mg orally twice a day
Duration of therapy: 5 days
Comments:
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If you have kidney disease, your healthcare provider may prescribe a lower dose. Talk to your healthcare provider to make sure you receive the correct Dose Pack.
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Nirmatrelvir must be coadministered with ritonavir; the dosage consists of 3 tablets (2 nirmatrelvir 150-mg tablets and 1 ritonavir 100-mg tablet), and all 3 of those tablets should be administered together. Prescriptions should specify the numeric dose of each active component within this product.
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This product should be started as soon as possible after COVID-19 has been diagnosed and within 5 days of symptom onset.
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If hospitalization is required due to severe/critical COVID-19 after starting treatment with this product, the patient should complete the full 5-day treatment course per health care provider's discretion.
Use: For the treatment of mild to moderate COVID-19 in adults who are at high risk for progression to severe COVID-19, including hospitalization or death
Usual Pediatric Dose for COVID-19 (EUA)
For investigational use only
Use: Patients 12 to 18 years old weighing at least 40 kg:
Nirmatrlvir: 300 mg orally twice a day
Ritonavir: 100 mg orally twice a day
Duration of therapy: 5 days
Comments:
- If you have kidney disease, your healthcare provider may prescribe a lower dose. Talk to your healthcare provider to make sure you receive the correct Dose Pack.
- The US FDA issued an EUA to allow the emergency use of the unapproved product, nirmatrelvir co-packaged with ritonavir, for the treatment of mild to moderate COVID-19 in are at high risk for progression to severe COVID-19, including hospitalization or death; this product is not approved by the US FDA for this use.
- Nirmatrelvir must be coadministered with ritonavir; the dosage consists of 3 tablets (2 nirmatrelvir 150-mg tablets and 1 ritonavir 100-mg tablet), and all 3 of those tablets should be administered together. Prescriptions should specify the numeric dose of each active component within this product.
- This product should be started as soon as possible after COVID-19 has been diagnosed and within 5 days of symptom onset.
- If hospitalization is required due to severe/critical COVID-19 after starting treatment with this product, the patient should complete the full 5-day treatment course per health care provider's discretion.
Before Taking
You should not use Paxlovid if you are allergic to the active ingredients nirmatrelvir and ritonavir, or any of the inactive ingredients. Click here for a full list of Paxlovid ingredients.
Some drugs should not be used with Paxlovid, such as those listed below.
- alfuzosin, colchicine;
- sildenafil (Revatio) when used to treat pulmonary arterial hypertension (PAH);
- pain medicine--pethidine, piroxicam, propoxyphene;
- heart medicine--amiodarone, dronedarone, flecainide, propafenone, quinidine, ranolazine;
- antipsychotic medicine--lurasidone, pimozide, clozapine;
- ergot medicine--dihydroergotamine, ergotamine, methylergonovine;
- cholesterol-lowering medicine--lovastatin, simvastatin; or
- a sedative--triazolam, oral midazolam.
Paxlovid should not be started immediately after discontinuation of any of the following drugs:
- rifampin;
- St. John's Wort;
- a cancer medicine--apalutamide; or
- seizure medicine--carbamazepine, phenobarbital, phenytoin.
Tell your doctor if:
- you have liver problems or a liver disease such as hepatitis;
- you have kidney problems;
- you have an HIV-1 infection;
- you are pregnant or breastfeeding; or
- you have any serious or chronic disease.
Pregnancy
Tell your healthcare provider right away if you are or if you become pregnant. It is not known if Paxlovid can harm your unborn baby. Ritonavir can make birth control pills or skin patches less effective. Ask your doctor about other birth control options such as an injection, implant, vaginal ring, condom, diaphragm, cervical cap, or contraceptive sponge.
Breastfeeding
Tell your healthcare provider are breastfeeding or plan to breastfeed. It is not known if Paxlovid can pass into your breast milk. Talk to your healthcare provider about the best way to feed your baby during treatment withthis medicine.
What happens if I miss a dose?
If you miss a dose of Paxlovid within 8 hours of the time it is usually taken, take it as soon as you remember. If you miss a dose by more than 8 hours, skip the missed dose and take the next dose at your regular time. Do not take 2 doses of Paxlovid at the same time.
What happens if I overdose?
Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.
Paxlovid side effects
Get emergency medical help if you have signs of an allergic reaction (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling).
Paxlovid may cause serious side effects.
Call your doctor at once if you have:
- liver problems symptoms include loss of appetite, stomach pain (upper right side), tiredness, itching, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).
Ritonavir affects your immune system, which may cause certain side effects (even weeks or months after you've taken nirmatrelvir and ritonavir). Tell your doctor if you have:
- signs of a new infection--fever, night sweats, swollen glands, cold sores, cough, wheezing, diarrhea, weight loss;
- trouble speaking or swallowing, problems with balance or eye movement, weakness or prickly feeling; or
- swelling in your neck or throat (enlarged thyroid), menstrual changes, impotence.
Common side effects of Paxlovid
- changes in your sense of taste;
- diarrhea;
- elevated blood pressure; or
- muscle pain.
This is not a complete list of side effects, and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
See more: Paxlovid Side EffectsWhat other drugs will affect Paxlovid?
Sometimes it is not safe to use certain medicines at the same time. Some drugs can affect your blood levels of other drugs you use, which may increase side effects or make the medicines less effective.
Many drugs can affect Paxlovid and some drugs should not be used at the same time. Paxlovid can interact with other medicines causing severe or life-threatening side effects or death. Tell your doctor about all other medicines you use. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here.
Do not take Paxlovid if you are taking any of the following medicines: alfuzosin, amiodarone, apalutamide, carbamazepine, colchicine, dihydroergotamine, dronedarone, eletriptan, eplerenone, ergotamine, finerenone, flecainide, flibanserin, ivabradine, lomitapide, lovastatin, lumacaftor/ivacaftor, lurasidone, methylergonovine, midazolam (oral), naloxegol, phenobarbital, phenytoin, pimozide, primidone, propafenone, quinidine, ranolazine, rifampin, rifapentine, St. John’s Wort (hypericum perforatum), sildenafil (Revatio®, Liqrev®) for pulmonary arterial hypertension, silodosin, simvastatin, tolvaptan, triazolam, ubrogepant, voclosporin.
These are not the only medicines that may cause serious or life-threatening side effects if taken with Paxlovid. It is very important to tell your healthcare provider about all of the medicines you are taking because additional laboratory tests or changes in the dose of your other medicines may be necessary during treatment with this Paxlovid. Your healthcare provider may also tell you about specific symptoms to watch out for that may indicate that you need to stop or decrease the dose of some of your other medicines.
To check for interactions with Paxlovid click on the link below.