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Paxlovid (nirmatrelvir/ritonavir)

Indications: - outpatient treatment of Covid-19* (emergency use authorization) - ASAP within 5 days of symptom onset * patients at average risk for progression to severe disease do not benefit [33] * significantly lowers rates of hospitalization & death due to Covid-19 in elderly (>= 65 years) [14] * no evidence of benefit in younger patients [14] * 51% lower risk of hospitalization within 30 days of Covid-19 diagnosis across all age groups >= 18 years than without Paxlovid [17] * reduces risk of long Covid-19 regardless of vaccination status (RR=0.74) [19] - reduces risk of post Covid-19 death (RR=0.52) [19] * reduces risk of hospitalization (RR=0.6) & death (RR=0.29) among adults age >= 50 years 90% of whom with >= 3 vaccines all during the Omicron wave [24] * effectively reduces risks of death, hospitalization, death or hospitalization, ED visits, ICU admission, & extra oxygen requirement [25] * in the Omincron era Feb 1, 2022 - Feb 3, 2023, Paxlovid decreased risk of hospitalization or death in severely immunocompromised patients but not in lower risk patients including elderly > 70 years with serious comordibity [26] * effect on long Covid-19 - only thromboembolic events seem to be reduced by Paxlovid [29] - reduction in incidence of long Covid-19 (absolute risk reduction = 4.5%) [30] - does not reduce risk of long Covid-19 [31,34] Contraindications: - co-administration with drugs highly dependent on CYP3A4 for clearance & for which elevated levels may have serious consequences - pausing of drug for 8-10 days may permit Paxolovid administration [23] - co-administration with potent CYP3A4 inducers may reduce nirmatrelvir &/or ritonavir plasma concentrations - pausing of drug will not permit Paxlovid administration [23] - see drug interactions below for specific interactions & recommendations - no improvement vs placebo for Paxlovid as prevention of Covid-19 after high-risk exposure [10] * alternative agents: molnupiravir (Lagevrio), remdesivir (Veklury) Dosage: - nirmatrelvir 300 mg + ritonavir 100 mg - 2 nirmatrelvir 150 mg tablets + 1 ritonavir 100 mg tablet - tablets taken twice a day for 5 days Tabs: copackaged nirmatrelvir 150 mg (2 tablets) + ritonavir 100 mg (1 tablet) Dosage adjustment in renal failure: - for eGFR of 30-60 mL/min - nirmatrelvir 150 mg (1 tablet) + ritonavir 100 mg twice daily for 5 days - Paxlovid not recommended if eGFR < 30 mL/min dose pack: 300 mg nirmatrelvir/100 mg ritonavir & 150 mg nirmatrelvir/100 mg ritonavir Adverse effects: - dysgeusia, diarrhea, abdominal pain, nausea - hypertension. myalgia, malaise - anaphylaxis, hypersensitivity - hepatotoxicity: hepatic transaminase elevations, clinical hepatitis, & jaundice may result from ritonavir (also see ritonavir) - resistance to HIV protease inhibitors - some patients experience viral rebound after taking Paxlovid [10,12] - more-severe COVID-19 increases risk of rebound [32] - most cases mild, but reports of severe cases - rebound in SARS-CoV2 RNA around 10-12 days after initial confirmation - symptom recurrence common after 2 consecutive symptom-free days without Paxlovid [16] - uncommon among Paxlovid users (1.0% vs 0.6% for non-users) [21] - neither of 2 Paxlovid users & 12 of 68 non-users with viral rebound died of Covid-19 [21] - symptomatic rebound in 32% of 130 Paxlovid users vs 20% of 241 non-users [32] - virologic rebound - occurs in ~20% of patients who receive Paxlovid vs < 2% in those who do not [28] - occurs in 27% of paxlovid treated vs. 7% of untreated patients [32] - no increased risk of rebound [25] - emergence of SARS-CoV-2 strains resistant to nirmatrelvir after treatment with Paxlovid is rare, independent of virologic rebound [35] Drug interactions: - derived from ref [23] - ritonavir is an inhibitor of CYP3A4 (see ritonavir) - increases concentration of drugs metabolized by CYP3A4 - both nirmatrelvir & ritonavir are substrates of CYP3A4 - 80% of CYP3A4 activity resolves within 3 days of stopping ritonavir, thus most paused medications can be resumed 3 days after 5 days of Paxlovid, & if no harm from the brief pause, 5 days after [23] - strong CYP3A4 inhibitors will not result in a clinically significant increase in nirmatrelvir/ritonavir concentrations [23] - strong inducers of CYP3A4 may reduce efficacy of nirmatrelvir [23] - these interaction cannot be prevented & Paxlovid is contraindicated - moderate inducers of CYP3A4 are unlikely to cause a problem [23] - alphabetical listing of interacting & potentially interacting medications sorted by generic name (see below for listing sorted by Tradename)* [23] - Abemaciclib (Verzenio) - potential interaction, consider pause 8 days* - Acalabrutinib (Calquence) - pause 8 days* - Afatinib (Gilotrif) - potential interaction, consider pause 8 days - Alfuzosin (Uroxatral) - pause 8 days - Aliskiren (Tekturna, Rasilez) - pause 8 days - Alprazolam (Xanax, Niravam) - potential interaction, consider pause 8 days - Amiodarone (Cordarone, Pacerone) - Paxlovid contraindicated due to prolonged 1/2life - Apalutamide (Erleada) - Paxlovid contraindicated due to strong CYP3A4 inducer - Apixaban (Eliquis) - pause 8 days - Aprepitant (Emend) - potential interaction, consider pause 8 days - Aripiprazole (Abilify) - potential interaction, consider pause 8 days - Atorvastatin (Lipitor) - potential interaction, consider pause 8 days - Avanafil (Stendra) - Bepridil (Vascor, Angopril, Cordium) - pause 8 days - Bosentan (Tracleer) - pause 8 days - Bosutinib (Bosulif) - pause 8 days - Buspirone (BuSpar) - potential interaction, consider pause 8 days - Carbamazepine* (Tegretol) - Paxlovid contraindicated due to strong CYP3A4 inducer [23] - Ceritinib, pelitinib (Zykadia)- potential interaction, consider pause 8 days - Cisapride (Propulsid) - pause 8 days - Cladrabine (Leustatin) - potential interaction, consider pause 8 days - Clobazam (ONFI, Frisium, Urbanol) - potential interaction, consider pause 8 days - Clonazepam (Klonopin) - Clopidogrel (Plavix) - pause 8 days - Clorazepate (Tranxene) - pause 8 days - Clozapine (Clozaril) - pause 8 days - Colchicine (Colcrys) in patients with renal &/or hepatic impairment - pause 8 days - Codeine (Phenergan) - Cyclosporine, cyclosporine-A (Sandimmune, Neoral) - pause 8 days - Dabigatran (Pradaxa) - potential interaction, consider pause 8 days - Dasatinib (Sprycel) - potential interaction, consider pause 8 days - Dextropropoxyphene (Dolene) - pause 8 days - Diazepam (Vallium) - pause 8 days - Digoxin (Lanoxin) - potential interaction, consider pause 8 days - Disopyramide (Norpace) - pause 8 days - Dofetilide (Tikosyn)- pause 8 days - Domperidone (Motilium) - pause 8 days - Dronedarone (Multaq) - pause 8 days - Edoxaban (Savaysa) - potential interaction, consider pause 8 days - Elbasvir/grazoprevir (Zepatier) - pause 8 days - Encorafenib (Mektovi)- potential interaction, consider pause 8 days - Enzalutamide (Xtandi) - Paxlovid contraindicated due to strong CYP3A4 inducer - Eplerenone (Inspra) - Ergot derivatives, ergometrine, ergotamine ((Migranal, Trudhesa) - pause 8 days - Erlotinib (Tarceva) - potential interaction, consider pause 8 days - Estazolam (ProSom) - pause 8 days - Ethosuximide (Zarontin) - potential interaction, consider pause 8 days - Everolimus (Afinitor) - pause 8 days - Flecainide (Tambocor) - pause 8 days - Fentanyl (Sublimaze, Fentora... Lazanda)- potential interaction, consider pause 8 days - Flibanserin (Addyi, Girosa) - Flunitrazepam (Rohypnol) - potential interaction, consider pause 8 days - Flurazepam (Dalmane) - pause 8 days - Fostamatinib (Tavalisse) - potential interaction, consider pause 8 days - Gilteritinib (Xospata) - potential interaction, consider pause 8 days - Glecaprevir/pibrentasvir (Mavyret) - pause 8 days - Haloperidol (Haldol) - potential interaction, consider pause 8 days - Hydrocodone (Zohydro ER, Hysingla ER) - Ibrutinib (Imbruvica) - pause 8 days - Iloperidone, hoperidone (Fanapt) - potential interaction, consider pause 8 days - Imatinib (Gleevec) - potential interaction, consider pause 8 days - Ivabradine (Corlanor, Lancora) - pause 8 days - Ivosidenib (Tibsovo) - Paxlovid contraindicated due to strong CYP3A4 inducer - Lercanidipine (Zanidip) - pause 8 days - Lidocaine (Xylocaine) - potential interaction, consider pause 8 days - Lomitapide (Juxtapid) - Lovastatin (Mevacor, Altocor, Altoprev) - Lumateperone (Caplyta) - pause 8 days - Lurasidone (Latuda) - pause 8 days - Meperidine, pethidine (Demerol) - Midazolam, oral (Buccolam) - pause 8 days - Midostaurin (Rydapt) - pause 8 days - Mexiletine (Mexitil) - Neratinib (Nerlynx) - pause 8 days - Nilotinib (Tasigna) - potential interaction, consider pause 8 days - Olaparib (Lynparza) - potential interaction, consider pause 8 days - Oxycodone (Roxicodone, OxyContin ...) - potential interaction, consider pause 8 days - Palbociclib (Ibrance) - potential interaction, consider pause 8 days - Pazopanib (Votrient) - potential interaction, consider pause 8 days - Phenprocoumon (Marcoumar...) - potential interaction, consider pause 8 days - Phenobarbital (Luminal...) - Paxlovid contraindicated due to strong CYP3A4 inducer - Phenytoin (Dilantin...) - Paxlovid contraindicated due to strong CYP3A4 inducer - Pimozide (Orap) - pause 8 days - Piroxicam (Feldene) - Primidone (Mysoline...) - Paxlovid contraindicated due to strong CYP3A4 inducer - Propafenone (Rythmol, Baxarytmon) - pause 8 days - Propoxyphene (Darvon) - Quetiapine (Seroquel) - pause 8 days - Quinidine (Quinaglute, Quinalan, Quinidex, Quinora)- pause 8 days - Ranolazine (Ranexa) - pause 8 days - Reboxetine (Vestra, Edronax...) - potential interaction, consider pause 8 days - Ribociclib (Kisqali) - potential interaction, consider pause 8 days - Riociguat (Adempas) - potential interaction, consider pause 8 days - Rifampin/Rifampicin (Rifadin) - Paxlovid contraindicated due to strong CYP3A4 inducer - Rifapentine (Priftin) - Paxlovid contraindicated due to strong CYP3A4 inducer - Rivaroxaban (Xarelto) - pause 8 days - Rosuvastatin (Crestor) - potential interaction, consider pause 8 days - Salmeterol (Serevent) - pause 8 days - Saxagliptin (Onglyza) - potential interaction, consider pause 8 days - Sildenafil for pulmonary hypertension (Revatio) - pause 8 days - Silodosin (Rapaflo) - Simvastatin (Zocor) - pause 8 days, metabolized 100% by CYP3A4 - Sirolimus, rapamycin (Rapamune) - pause 8 days - Sofosbivir/velpatasvir/voxilaprevir (Vosevi) - potential interaction, consider pause 8 days - Suvorexant (Belsomra) - St. John's wort (Hypericum perforatum) - Paxlovid contraindicated due to strong CYP3A4 inducer - Sunitinib (Sutent) - potential interaction, consider pause 8 days - Tacrolimus* (Prograf...) - pause 8 days, therapeutic drug monitoring [22,23] - Tadalafil for erectile dysfunction (Cialis) - Tadalafil for pulmonary hypertension (Adcirca) - pause 8 days - Tamsulosin (Flomax, Urolosin) - Tiagabine (Gabitril) - potential interaction, consider pause 8 days - Ticagrelor (Brilinta) - pause 8 days - Tramadol (Ultram) - Trazodone (Desyrel...) - potential interaction, consider pause 8 days - Triazolam (Halcion) - pause 8 days - Vardenafil (Levitra, Staxyn) - Vinblastine (Velban, Velsar)- potential interaction, consider pause 8 days - Vincristine (Oncovin)- potential interaction, consider pause 8 days - Venetoclax (Venclexta) - pause 8 days - Voclosporin (Lupkynistm) - pause 8 days - Vorapaxar (Zontivity) - Warfarin (Coumadin)- potential interaction, consider pause 8 days * Tradename(s) in parentheses * no action needed unless specified * pause of 8 days: pause during Paxlovid administration + 3 days after - same alphabetical listing sorted by Tradename - (Abilify) Aripiprazole - potential interaction, consider pause 8 days - (Adcirca) Tadalafil for pulmonary hypertension - pause 8 days - (Addyi, Girosa) Flibanserin - (Adempas) Riociguat - potential interaction, consider pause 8 days - (Afinitor) Everolimus - pause 8 days - (Altocor, Mevacor, Altoprev) Lovastatin - (Altoprev, Mevacor, Altocor) Lovastatin - (Angopril, Vascor, Cordium) Bepridil - pause 8 days - (Baxarytmon, Rythmol) Propafenone - pause 8 days - (Belsomra) Suvorexant - (Bosulif) Bosutinib - pause 8 days - (Brilinta) Ticagrelor - pause 8 days - (Buccolam) Midazolam, oral - pause 8 days - (BuSpar) Buspirone - potential interaction, consider pause 8 days - (Calquence) Acalabrutinib - pause 8 days* - (Caplyta) Lumateperone - pause 8 days - (Cialis) Tadalafil for erectile dysfunction - (Clozaril) Clozapine - pause 8 days - (Colcrys) Colchicine in patients with renal &/or hepatic impairment - pause 8 days - (Cordarone, Pacerone) Amiodarone - Paxlovid contraindicated due to prolonged 1/2life - (Cordium, Angopril, Vascor) Bepridil - pause 8 days - (Corlanor, Lancora) Ivabradine - pause 8 days - (Coumadin) Warfarin - potential interaction, consider pause 8 days - (Crestor) Rosuvastatin - potential interaction, consider pause 8 days - (Dalmane) Flurazepam - pause 8 days - (Darvon) Propoxyphene - (Demerol) Meperidine, pethidine - (Desyrel...) Trazodone - potential interaction, consider pause 8 days - (Dilantin...) Phenytoin - Paxlovid contraindicated due to strong CYP3A4 inducer - (Dolene) Dextropropoxyphene - pause 8 days - (Edronax, Vestra ...) Reboxetine - potential interaction, consider pause 8 days - (Eliquis) Apixaban - pause 8 days - (Emend) Aprepitant - potential interaction, consider pause 8 days - (Erleada) Apalutamide - Paxlovid contraindicated due to strong CYP3A4 inducer - (Fanapt) Iloperidone, hoperidone - potential interaction, consider pause 8 days - (Feldene) Piroxicam - (Fentora, Sublimaze, Lazanda ...) Fentanyl - potential interaction, consider pause 8 days - (Flomax, Urolosin) Tamsulosin - (Frisium, ONFI, Urbanol) Clobazam - potential interaction, consider pause 8 days - (Gabitril) Tiagabine - potential interaction, consider pause 8 days - (Gilotrif) Afatinib - potential interaction, consider pause 8 days - (Girosa, Addyi) Flibanserin - (Gleevec) Imatinib - potential interaction, consider pause 8 days - (Halcion) Triazolam - pause 8 days - (Haldol) Haloperidol - potential interaction, consider pause 8 days - (Hypericum perforatum) St. John's wort - Paxlovid contraindicated due to strong CYP3A4 inducer - (Hysingla ER, Zohydro ER) Hydrocodone - (Ibrance) Palbociclib - potential interaction, consider pause 8 days - (Imbruvica) Ibrutinib - pause 8 days - (Inspra) Eplerenone - (Juxtapid) Lomitapide - (Kisqali) Ribociclib - potential interaction, consider pause 8 days - (Klonopin) Clonazepam - (Lancora, Corlanor) Ivabradine - pause 8 days - (Lanoxin) Digoxin - potential interaction, consider pause 8 days - (Latuda) Lurasidone - pause 8 days - (Lazanda, Sublimaze, Fentora ...) Fentanyl - potential interaction, consider pause 8 days - (Leustatin) Cladrabine - potential interaction, consider pause 8 days - (Levitra, Staxyn) Vardenafil - (Lipitor) Atorvastatin - potential interaction, consider pause 8 days - (Luminal...) Phenobarbital - Paxlovid contraindicated due to strong CYP3A4 inducer - (Lupkynistm) Venetoclax - pause 8 days - (Lynparza) - potential interaction, consider pause 8 days - (Marcoumar...) Phenprocoumon - potential interaction, consider pause 8 days - (Mavyret) Glecaprevir/pibrentasvir - pause 8 days - (Mektovi) Encorafenib - potential interaction, consider pause 8 days - (Mevacor, Altocor, Altoprev) Lovastatin - (Mexitil) Mexiletine - (Migranal, Trudhesa) Ergot derivatives, ergometrine, ergotamine - pause 8 days - (Motilium) Domperidone - pause 8 days - (Multaq) Dronedarone - pause 8 days - (Mysoline...) Primidone - Paxlovid contraindicated due to strong CYP3A4 inducer - (Neoral, Sandimmune) Cyclosporine, cyclosporine-A - pause 8 days - (Nerlynx) Neratinib - pause 8 days - (Niravam, Xanax) Alprazolam - potential interaction, consider pause 8 days - (Norpace) Disopyramide - pause 8 days - (Oncovin) Vincristine - potential interaction, consider pause 8 days - (ONFI, Frisium, Urbanol) Clobazam - potential interaction, consider pause 8 days - (Onglyza) Saxagliptin - potential interaction, consider pause 8 days - (Orap) Pimozide - pause 8 days - (OxyContin, Roxicodone ...) Oxycodone - potential interaction, consider pause 8 days - (Pacerone, Cordarone) Amiodarone - Paxlovid contraindicated due to prolonged 1/2life - (Phenergan) Codeine - (Plavix) Clopidogrel - pause 8 days - (Pradaxa) Dabigatran - potential interaction, consider pause 8 days - (Priftin) Rifapentine - Paxlovid contraindicated due to strong CYP3A4 inducer - (Prograf...) Tacrolimus* - pause 8 days, therapeutic drug monitoring [22,23] - (Propulsid) Cisapride - pause 8 days - (ProSom) Estazolam - pause 8 days - (Quinaglute, Quinalan, Quinidex, Quinora) Quinidine - pause 8 days - (Ranexa) Ranolazine - pause 8 days - (Rapaflo) Silodosin - (Rapamune) Sirolimus, rapamycin - pause 8 days - (Rasilez, Tekturna) Aliskiren - pause 8 days - (Revatio) Sildenafil for pulmonary hypertension - pause 8 days - (Rifadin) Rifampin/Rifampicin - Paxlovid contraindicated due to strong CYP3A4 inducer - (Rohypnol) Flunitrazepam - potential interaction, consider pause 8 days - (Roxicodone, OxyContin ...) Oxycodone - potential interaction, consider pause 8 days - (Rydapt) Midostaurin - pause 8 days - (Rythmol, Baxarytmon) Propafenone - pause 8 days - (Sandimmune, Neoral) Cyclosporine, cyclosporine-A - pause 8 days - (Savaysa) Edoxaban - potential interaction, consider pause 8 days - (Serevent) Salmeterol - pause 8 days - (Seroquel) Quetiapine - pause 8 days - (Sprycel) Dasatinib - potential interaction, consider pause 8 days - (Staxyn, Levitra) Vardenafil - (Stendra) Avanafil - (Sublimaze, Fentora, Lazanda ...) Fentanyl - potential interaction, consider pause 8 days - (Sutent) Sunitinib - potential interaction, consider pause 8 days - (Tambocor) Flecainide - pause 8 days - (Tarceva) Erlotinib - potential interaction, consider pause 8 days - (Tasigna) Nilotinib - potential interaction, consider pause 8 days - (Tavalisse) Fostamatinib - potential interaction, consider pause 8 days - (Tegretol) Carbamazepine* - Paxlovid contraindicated due to strong CYP3A4 inducer [23] - (Tekturna, Rasilez) Aliskiren - pause 8 days - (Tibsovo) Ivosidenib - Paxlovid contraindicated due to strong CYP3A4 inducer - (Tikosyn) Dofetilide - pause 8 days - (Tracleer) Bosentan - pause 8 days - (Tranxene) Clorazepate - pause 8 days - (Trudhesa, Migranal) Ergot derivatives, ergometrine, ergotamine - pause 8 days - (Ultram) Tramadol - (Urbanol, ONFI, Frisium) Clobazam - potential interaction, consider pause 8 days - (Urolosin, Flomax) Tamsulosin - (Uroxatral) Alfuzosin - pause 8 days - (Vallium) Diazepam - pause 8 days - (Vascor, Angopril, Cordium) Bepridil - pause 8 days - (Velban, Velsar) Vinblastine - potential interaction, consider pause 8 days - (Venclexta) Venetoclax - pause 8 days - (Verzenio) Abemaciclib - potential interaction, consider pause 8 days* - (Vestra, Edronax...) Reboxetine - potential interaction, consider pause 8 days - (Vosevi) Sofosbivir/velpatasvir/voxilaprevir - potential interaction, consider pause 8 days - (Votrient) Pazopanib - potential interaction, consider pause 8 days - (Xanax, Niravam) Alprazolam - potential interaction, consider pause 8 days - (Xarelto) Rivaroxaban - pause 8 days - (Xospata) Gilteritinib - potential interaction, consider pause 8 days - (Xtandi) Enzalutamide - Paxlovid contraindicated due to strong CYP3A4 inducer - (Xylocaine) Lidocaine - potential interaction, consider pause 8 days - (Zanidip) Lercanidipine - pause 8 days - (Zarontin) Ethosuximide - potential interaction, consider pause 8 days - (Zepatier) Elbasvir/grazoprevir - pause 8 days - (Zocor) Simvastatin - pause 8 days, metabolized 100% by CYP3A4 - (Zohydro ER, Hysingla ER) Hydrocodone - (Zontivity) Vorapaxar - (Zykadia) Ceritinib, pelitinib - potential interaction, consider pause 8 days Clinical significance: - Pfizer reports Paxlovid is 89% effective, compared to a placebo, at preventing hospitalization or death in patients with COVID-19 who are at high risk of severe complications if given within 3 days of symptom onset [2,5,6] - NEJM article confirms 89% efficacy [9] - monitor for effects of drug interactions for 5-day duration of Paxlovid treatment & for at least 3-5 days after treatment completion [8] - adults prescribed Paxlovid within 5 days of diagnosis had a 51% lower risk of hospitalization within 30 days of diagnosis than without [17] - reduces risk of hospitalization (RR=0.6) & death (RR=0.29) among adults age >= 50 years 90% of whom with >= 3 vaccines all during the Omicron wave [24] Structure: - combination of nirmatrelvir (PF-0732133)* & ritonavir Mechanism of action: - boosting with ritonavir, a strong CYP3A inhibitor, is required to increase the exposure of nirmatrelvir to a concentration effective against SARS-CoV2 [8] * see ref [3] for structure) Notes: - free in 2022 & 2023 courtesy of the U.S. government - Pfizer has said it will price Paxlovid in 2024 at $1390 for the 5 day course - U.S. government has so far purchased 20 million courses of Paxlovid, priced at ~$530 each, a discount for buying in bulk [20] - nearly 6 million Americans have taken Paxlovid for free, courtesy of the federal government [20] - Pfizer has applied for full FDA approval of Paxlovid in June of 2022, but so far only emergency use authorization has been granted [20] - federal law restricts Medicare Part D from covering medications without full FDA-approval [20]

Interactions

drug interactions

Related

COVID-19

General

antiviral combination

References

  1. Pfizer Press Release. Nov 5, 2021 Pfizer's Novel COVID-19 Oral Antiviral Treatment Candidate Reduced Risk of Hospitalization or Death by 89% in Interim Analysis of Phase 2/3 EPIC-HR Study. https://www.pfizer.com/news/press-release/press-release-detail/pfizers-novel-covid-19-oral-antiviral-treatment-candidate
  2. Goodman B Pfizer Says Its COVID-19 Pill Is Highly Effective. Medscape. November 05, 2021 https://www.medscape.com/viewarticle/962390
  3. Halford B Pfizer unveils its oral SARS-CoV-2 inhibitor. Chemical & Engineering News. April 7, 2021 https://cen.acs.org/acs-news/acs-meeting-news/Pfizer-unveils-oral-SARS-CoV/99/i13
  4. A Study of PF-07321332/Ritonavir in Nonhospitalized High Risk Adult Participants With COVID-19. ClinicalTrial.gov https://clinicaltrials.gov/ct2/show/NCT04960202
  5. AMA Morning Rounds. November 8, 2021 - New York Times https://www.nytimes.com/2021/11/05/health/pfizer-covid-pill.html - Johnson CY Antiviral pills from Pfizer, Merck, show promise against worst covid-19 outcomes. Washington Post. November 5, 2021 https://www.washingtonpost.com/health/2021/11/05/pfizer-covid-pill/
  6. Erman M, Beasley D Pfizer Says COVID-19 Pill Near 90% Effective in Final Analysis. Medscape. December 14, 2021 https://www.medscape.com/viewarticle/964750
  7. McNamara D FDA Authorizes Pfizer Antiviral Pill for COVID-19. Medscape. December 22, 2021 https://www.medscape.com/viewarticle/965398
  8. Pearson A Caution: Paxlovid Interacts With Many Heart Meds. The Skeptical Cardiologist asks clinicians and patients to take note. MedPage Today. Jan 17, 2022 https://www.medpagetoday.com/opinion/skeptical-cardiologist/96692 - NIH Coovid-19 Treatment Guidelines. Dec 30, 2021 The COVID-19 Treatment Guidelines Panel's Statement on Potential Drug-Drug Interactions Between Ritonavir-Boosted Nirmatrelvir (Paxlovid) and Concomitant Medications. Statement on Paxlovid Drug-Drug Interactions https://www.covid19treatmentguidelines.nih.gov/therapies/statement-on-paxlovid-drug-drug-interactions/
  9. Hammond J, Leister-Tebbe H, Gardner A et al Oral Nirmatrelvir for High-Risk, Nonhospitalized Adults with Covid-19. N Engl J Med. 2022. Feb 16. PMID: 35172054 https://www.nejm.org/doi/full/10.1056/NEJMoa2118542
  10. Walker M NIH Probes Palovid Relapses; Pandemic of the Unvaxxed No More? Musk Disses Wellbutrin. A daily roundup of news on Covid-19 and the rest of medicine. MedPage Today May 2, 2022 https://www.medpagetoday.com/infectiousdisease/covid19/98500
  11. Ganio M Paxlovid Is Here: A Pharmacist's Prescribing Pearls. Medscape. May 03, 2022 https://www.medscape.com/viewarticle/973260
  12. Fiore K What Do We Know About Paxlovid Rebound? And how should clinicians handle relapses after a 5-day course? MedPage Today May 6, 2022 https://www.medpagetoday.com/special-reports/exclusives/98584
  13. Centers for Disease Control & Prevention (CDC) Health Alet Network. May 24, 2022 COVID-19 Rebound After Paxlovid Treatment. https://emergency.cdc.gov/han/2022/han00467.asp
  14. Hein I Far Fewer Deaths During Omicron for Seniors Treated With Paxlovid. - Little apparent effect observed in patients ages 40 to 64, however. MedPage Today August 24, 2022 https://www.medpagetoday.com/infectiousdisease/covid19/100382 - Arbel R, Wolff Sagy Y, Hoshen M et al Nirmatrelvir Use and Severe Covid-19 Outcomes during the Omicron Surge. N Engl J Med. 2022. Aug 24. Not yet indeed in PubMed https://www.nejm.org/doi/full/10.1056/NEJMoa2204919
  15. Bronze MS Rapid Review Quiz: COVID-19 Updates Medscape. September 28, 2022 https://reference.medscape.com/viewarticle/980879 - Arbel R, Sagy WY, Hoshen M et al Nirmatrelvir Use and Severe Covid-19 Outcomes during the Omicron Surge. N Engl J Med. 2022 Sep 1;387(9):790-798. PMID: 36001529 PMCID: PMC9454652 Free PMC article https://www.nejm.org/doi/10.1056/NEJMoa2204919
  16. Smith DM, Li JZ, Moser C et al Recurrence of Symptoms Following a 2-Day Symptom Free Period in Patients With COVID-19. JAMA Netw Open. 2022;5(10):e2238867. PMID: 36301549 https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2797789
  17. Phend C Paxlovid Vindicated for Younger COVID Patients. CDC study supports similar benefit in those under 50 as in seniors. MedPage Today November 22, 2022 https://www.medpagetoday.com/infectiousdisease/covid19/101874 - Shah MM, Joyce B, Plumb ID et al. Paxlovid Associated with Decreased Hospitalization Rate Among Adults with COVID-19 - United States, April-September 2022. MMWR Morb Mortal Wkly Rep. ePub: 22 November 2022 https://www.cdc.gov/mmwr/volumes/71/wr/mm7148e2.htm
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Components

nirmatrelvir ritonavir (Norvir, RTV)