Health Library

Nirmatrelvir/ritonavir (By mouth)

Treats coronavirus disease 2019 (COVID-19).

Brand Name(s):

Paxlovid 150MG;100MG Dose Pack, Paxlovid 300MG;100MG Dose Pack

When This Medicine Should Not Be Used:

How to Use This Medicine:

Tablet, Tablet

• Your doctor will tell you how much medicine to use. Do not use more than directed. Take this medicine within 5 days of the onset of COVID-19 symptoms.
• Swallow the tablet whole. Do not crush, break, or chew it.
• This medicine comes with a Fact Sheet for Patients, Parents, and Caregivers. Read and follow the information in the Fact Sheet carefully. Ask your doctor or pharmacist if you have any questions.
• Missed dose: If it is within 8 hours of the time it is usually taken, take it as soon as possible, and then go back to your regular schedule. If it is more than 8 hours, skip the missed dose and take your next dose at the regular time. Do not use extra medicine to make up for a missed dose.
• Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

• Do not use this medicine if you are also using alfuzosin, apalutamide, colchicine, eletriptan, eplerenone, finerenone, flibanserin, ivabradine, lomitapide, lovastatin, lumacaftor/ivacaftor, lurasidone, midazolam, naloxegol, pethidine, pimozide, ranolazine, rifampin, sildenafil, silodosin, simvastatin, St John's wort, tolvaptan, triazolam, ubrogepant, voclosporin, ergot medicine (including dihydroergotamine, ergotamine, methylergonovine), medicine for heart rhythm problems (including amiodarone, dronedarone, flecainide, propafenone, quinidine), or seizure medicine (including carbamazepine, phenobarbital, phenytoin, primidone).
• Some medicines can affect how nirmatrelvir/ritonavir works. Tell your doctor if you are using any of the following:
  • Aliskiren, atorvastatin, avanafil, bedaquiline, bosentan, clopidogrel, clozapine, cyclosporine, dasabuvir, digoxin, elbasvir/grazoprevir, elexacaftor/tezacaftor/ivacaftor, everolimus, fentanyl, glecaprevir/pibrentasvir, hydrocodone, ivacaftor, lidocaine, methadone, ombitasvir/paritaprevir/ritonavir, oxycodone, quetiapine, rifabutin, rifapentine, rimegepant, rosuvastatin, salmeterol, sirolimus, sofosbuvir/velpatasvir/voxilaprevir, suvorexant, tacrolimus, tadalafil, tamsulosin, tezacaftor/ivacaftor, ticagrelor, vardenafil, vorapaxar
  • Birth control pills (including ethinyl estradiol)
  • Blood pressure medicine (including amlodipine, diltiazem, felodipine, nicardipine, nifedipine)
  • Blood thinner (including dabigatran, rivaroxaban, warfarin)
  • Medicine to treat cancer (including abemaciclib, ceritinib, dasatinib, encorafenib, ibrutinib, ivosidenib, neratinib, nilotinib, venetoclax, vinblastine, vincristine)
  • Medicine to treat depression (including bupropion, trazodone)
  • Medicine to treat HIV (including atazanavir, bictegravir/emtricitabine/tenofovir, darunavir, efavirenz, maraviroc, tipranavir, zidovudine)
  • Medicine to treat infections (including clarithromycin, erythromycin, isavuconazonium, itraconazole, ketoconazole, voriconazole)
  • Steroid medicine (including betamethasone, budesonide, ciclesonide, dexamethasone, fluticasone, methylprednisolone, mometasone, triamcinolone)

Warnings While Using This Medicine:

• Tell your doctor if you are pregnant or planning to become pregnant. Birth control pills may not work as well to prevent pregnancy when used with this medicine. Use another form of birth control (including condoms or spermicide) along with your pills.
• Tell your doctor if you are breastfeeding, or if you have kidney disease, liver disease, or HIV infection.
• This medicine may cause the following problems:
  • Serious skin reactions, including toxic epidermal necrolysis, Stevens-Johnson syndrome
  • Liver problems
• Your doctor will do lab tests at regular visits to check on the effects of this medicine. Keep all appointments.
• Keep all medicine out of the reach of children. Never share your medicine with anyone.

Possible Side Effects While Using This Medicine:

If you notice these less serious side effects, talk with your doctor:

• Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
• Blistering, peeling, red skin rash
• Blurred vision, severe headache, slow or fast heartbeat, lightheadedness, dizziness
• Dark urine or pale stools, nausea, vomiting, loss of appetite, stomach pain, yellow skin or eyes

If you notice these less serious side effects, talk with your doctor:

• Change or loss of taste
• Diarrhea
• Muscle pain

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088

Last Updated: 9/6/2024