Paxlovid (Nirmatrelvir And Ritonavir)
Complete patient guide for uses, dosage, side effects, and safety information
Prescription RequiredQuick Facts
What Is Paxlovid Used For?
Paxlovid is a combination medicine containing two different tablets with active ingredients nirmatrelvir and ritonavir, specifically designed to treat COVID-19.
Primary Uses
Paxlovid is used to treat COVID-19 in adults who are at increased risk of progression to hospitalization or death.
How It Works
The medication works through a combination of two active ingredients: nirmatrelvir and ritonavir, which must be taken together to be effective.
New Medicine: This medicine is new or being used differently. Please report any side effects you experience.
How to Take Paxlovid
Your doctor will determine the right amount of Paxlovid for you based on whether you have kidney problems. The medication must be taken exactly as prescribed.
Dosage Instructions
The standard dose is two 150 mg tablets of nirmatrelvir together with one 100 mg tablet of ritonavir, taken every 12 hours. If you have reduced kidney function, your doctor may prescribe one 150 mg tablet of nirmatrelvir with one 100 mg tablet of ritonavir. Take the tablets at about the same time each morning and evening. The tablets can be taken with or without food and should be swallowed whole – do not chew, break, or crush them. Continue taking Paxlovid for 5 days until you finish the pack or until your doctor recommends stopping.
What If You Miss a Dose?
If you miss a dose within 8 hours of when you usually take it, 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.
Important: Never take 2 doses of Paxlovid at the same time. Nirmatrelvir must always be taken together with ritonavir.
Available Tablet Strengths
Side Effects
Like all medications, this medicine can cause side effects. Most are mild and temporary, but some require medical attention.
Common Side Effects
These side effects occur relatively frequently and usually don’t require emergency care:
- diarrhea
- vomiting
- headache
- high blood pressure
- changes in taste or metallic taste in mouth
- nausea
- abdominal pain
- generally feeling unwell
Seek immediate medical attention if you experience:
- severe allergic reaction including raw, painful and/or peeling skin, blisters, sore throat or mouth, or fever
- signs of allergic reaction including rash, itch, hives, swelling of face, tongue, lips, eyes, or throat
- feeling breathless, light-headed or dizzy
Important Warnings
There are several important safety considerations before taking Paxlovid, including serious drug interactions and medical conditions that require special attention.
Who Should Not Take Paxlovid
Do not take Paxlovid if you are allergic to nirmatrelvir, ritonavir, or any ingredients. You must not take it with certain medicines including: alfuzosin, silodosin (enlarged prostate medicines), ranolazine (chest pain medicine), pethidine (pain medicine), amiodarone, flecainide (heart rhythm medicines), certain cancer medicines (neratinib, apalutamide, enzalutamide, venetoclax), colchicine (gout medicine), certain mental health medicines (lurasidone, clozapine, cariprazine), heart failure medicines (eplerenone, ivabradine), ergometrine (bleeding medicine), simvastatin (cholesterol medicine), eletriptan (migraine medicine), finerenone (kidney disease medicine), naloxegol (constipation medicine), certain erectile dysfunction medicines (avanafil, vardenafil), sildenafil for lung blood pressure, diazepam (anxiety medicine), sleep medicines (triazolam, zolpidem), tolvaptan (kidney medicine), seizure medicines (carbamazepine, phenobarbital, phenytoin, primidone), rifampicin (tuberculosis medicine), lumacaftor/ivacaftor (cystic fibrosis medicine), and St. John’s Wort.
Medical Conditions to Discuss
Tell your doctor if you have or have had liver problems or kidney problems. During treatment, you may be at risk of developing certain side effects, so it’s important to understand these risks and monitor for them.
Pregnancy and Breastfeeding
You should not take Paxlovid if you are pregnant. Women of childbearing potential should use effective contraception before starting treatment and for 7 days after stopping treatment. Do not breastfeed while taking Paxlovid and for 48 hours after stopping treatment. Call your doctor immediately if you become pregnant while taking this medicine.
Serious Drug Interactions: Taking Paxlovid with certain medicines may cause serious or life-threatening side effects. Always tell your doctor about all medicines you are taking.
Drug Interactions
Many medicines can interact with Paxlovid and affect how it works or cause serious side effects. Always inform your doctor about all medications, vitamins, and supplements you are taking.
Check All Medications: Check with your doctor or pharmacist if you are not sure about what medicines, vitamins or supplements you are taking and if these affect Paxlovid.
- tamsulosin (enlarged prostate medicine)
- pain medicines (fentanyl, hydrocodone, oxycodone, methadone, piroxicam)
- heart medicines (digoxin, lidocaine, disopyramide, mavacamten)
- cancer medicines (afatinib, abemaciclib, ceritinib, dasatinib, nilotinib, encorafenib, ibrutinib, vinblastine, vincristine)
- mental health medicines (aripiprazole, brexpiprazole, haloperidol, risperidone, quetiapine)
- blood thinners (apixaban, clopidogrel, dabigatran, rivaroxaban, ticagrelor, warfarin)
- seizure medicines (clonazepam, lamotrigine)
- depression medicines (amitriptyline, fluoxetine, imipramine, nortriptyline, paroxetine, sertraline)
- allergy medicines (loratadine)
- infection medicines (atovaquone, clarithromycin, erythromycin, rifabutin, ketoconazole, isavuconazonium sulfate, voriconazole, itraconazole)
- parasite medicines (albendazole)
- HIV medicines (atazanavir, darunavir, efavirenz, fosamprenavir, maraviroc, nevirapine, saquinavir, tipranavir, raltegravir, zidovudine, bictegravir/emtricitabine/tenofovir)
- hepatitis C medicines (glecaprevir/pibrentasvir, sofosbuvir/velpatasvir/voxilaprevir)
- lung medicines (salmeterol)
- blood pressure medicines (amlodipine, diltiazem, felodipine, nifedipine, verapamil)
- cystic fibrosis medicines (ivacaftor, elexacaftor/tezacaftor/ivacaftor, tezacaftor/ivacaftor)
- diabetes medicines (saxagliptin)
- hormone medicines (ethinylestradiol)
- immune system medicines (ciclosporin, everolimus, tacrolimus, sirolimus)
- arthritis medicines (tofacitinib, upadacitinib)
- urination medicines (darifenacin)
- erectile dysfunction medicines (sildenafil, tadalafil)
- lung blood pressure medicines (bosentan, riociguat)
- cholesterol medicines (atorvastatin, rosuvastatin)
- sleep and anxiety medicines (alprazolam, midazolam, suvorexant, clorazepate)
- smoking cessation medicines (bupropion)
- anti-inflammatory medicines (betamethasone, budesonide, ciclesonide, dexamethasone, fluticasone, methylprednisolone, mometasone, triamcinolone)
Alcohol & Driving
Be cautious about activities that require alertness while taking Paxlovid.
Alcohol
No specific information is available about drinking alcohol while taking Paxlovid.
Driving and Operating Machinery
There is no specific information on the effect of Paxlovid on your ability to drive or use machines. Be careful before you drive or use any machines or tools until you know how Paxlovid affects you.
Storage
Store Paxlovid below 25°C in a cool, dry place away from moisture, heat, or sunlight. Do not store in the bathroom, near a sink, in the car, or on windowsills. Do not take after the expiry date. Keep where young children cannot reach it. If you no longer need the medicine or it is out of date, take it to any pharmacy for safe disposal.
Overdose Information
If you think you have taken too much Paxlovid, you may need urgent medical attention. Immediately phone the Poisons Information Centre (13 11 26), contact your doctor, or go to the Emergency Department at your nearest hospital. Do this even if there are no signs of discomfort or poisoning.
Frequently Asked Questions
Paxlovid should be taken for 5 days. Continue taking it until you finish the pack or until your doctor recommends stopping.
Yes, Paxlovid tablets can be taken with or without food.
If you miss a dose within 8 hours of when you usually take it, 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. Never take 2 doses at the same time.
No, do not stop taking Paxlovid or change the dosage without consulting with your doctor. It’s important to complete the full 5-day course.
The tablets should be swallowed whole and not chewed, broken, or crushed. If you have difficulty swallowing tablets, speak to your doctor about alternatives.
No, do not give your medicine to anyone else, even if they have the same condition as you. The dosage and suitability depend on individual medical factors.
Store Paxlovid below 25°C in a cool, dry place away from moisture, heat, or sunlight. Do not store it in the bathroom, near a sink, in the car, or on windowsills.
Important Disclaimer
This information is intended for general educational purposes only and should not be considered medical advice. Always consult your healthcare provider or pharmacist before starting, stopping, or changing any medication.
If you think you may have a medical emergency, call your doctor or emergency services immediately.