Provider Briefing: Paxlovid 150 Mg /100 Mg Dose Pack in 2026

For providers prescribing Paxlovid (Nirmatrelvir/Ritonavir) to high-risk COVID-19 patients with moderate renal impairment, the 150 Mg /100 Mg Dose Pack presents unique availability and prescribing challenges. While Paxlovid is not in formal shortage, the renal dose formulation requires additional attention at the point of prescribing to ensure patients can actually fill and start treatment within the critical 5-day window.

This article provides a clinical and operational overview of the current Paxlovid landscape for healthcare providers and prescribers.

Timeline: From EUA to Commercial Distribution

Understanding the supply history helps contextualize current availability:

• December 2021: FDA issues Emergency Use Authorization (EUA) for Paxlovid. U.S. government purchases and distributes the drug at no cost to patients.
• May 2023: Paxlovid receives full FDA approval for adults at high risk of severe COVID-19.
• March 2024: EUA-labeled Paxlovid stock must be returned or destroyed. The drug transitions fully to commercial distribution through normal wholesale pharmacy channels.
• 2025–2026: Pfizer maintains commercial supply. No formal FDA or ASHP shortage listing. However, spot shortages occur at the pharmacy level during COVID surges, disproportionately affecting the renal dose pack.

Prescribing Implications for the 150 Mg /100 Mg Dose Pack

The 150 Mg /100 Mg Dose Pack is indicated for patients with moderate renal impairment (eGFR 30 to <60 mL/min). Key prescribing considerations include:

Renal Dosing

The standard Paxlovid dose is Nirmatrelvir 300 mg (two 150 mg tablets) + Ritonavir 100 mg twice daily. For moderate renal impairment, the dose is reduced to Nirmatrelvir 150 mg + Ritonavir 100 mg twice daily. Paxlovid is not recommended for patients with eGFR <30 mL/min, and no dose adjustment data exists for this population.

Drug Interaction Management

Ritonavir's potent CYP3A4 inhibition creates a complex drug interaction profile. For the patient population requiring renal dosing — often older adults with multiple comorbidities — polypharmacy is common, making interaction screening critical.

Contraindicated combinations include:

• Lovastatin, Simvastatin (rhabdomyolysis risk)
• Amiodarone, Flecainide, Propafenone (arrhythmia risk)
• Ergot derivatives (ergot toxicity)
• Oral Midazolam, Triazolam (excessive sedation)
• Pimozide, Lurasidone (QT prolongation)
• Sildenafil for pulmonary arterial hypertension
• Colchicine in patients with renal or hepatic impairment

Medications requiring dose adjustment or temporary hold:

• Atorvastatin — hold or reduce dose during 5-day course
• Rivaroxaban, Apixaban — dose reduction or temporary hold per clinical judgment
• Tacrolimus, Cyclosporine, Sirolimus — significant dose reduction and therapeutic drug monitoring required
• Warfarin — monitor INR closely
• Quetiapine — reduce dose
• Inhaled Fluticasone — risk of Cushing syndrome with prolonged concurrent use

Strong CYP3A inducers (Rifampin, Carbamazepine, Phenytoin, Phenobarbital, St. John's Wort) are contraindicated as they may reduce Nirmatrelvir levels below therapeutic thresholds.

For a comprehensive interaction reference, see our Paxlovid drug interactions guide.

Hepatic Considerations

Paxlovid is contraindicated in severe hepatic impairment (Child-Pugh Class C). No dose adjustment is needed for mild impairment. Use caution and monitor in moderate hepatic impairment (Child-Pugh Class B).

Current Availability Picture

While Pfizer's commercial supply is adequate at the national level, pharmacy-level availability of the 150 Mg /100 Mg Dose Pack remains inconsistent due to:

• Low baseline stocking: Pharmacies typically stock 0–2 renal dose packs vs. 5–10+ standard dose packs
• Surge-driven stockouts: During COVID waves, pharmacies deplete renal dose inventory rapidly
• Cost-driven inventory management: At $1,400–$1,800 per course, pharmacies limit shelf inventory for slow-moving formulations
• Wholesaler lead times: Reorder from distributors may take 24–48 hours, which can exceed the treatment window

Cost and Access Considerations

Patient access barriers often compound availability challenges:

• Cash price: $1,400–$1,800 for a 5-day course
• Commercial insurance: Generally covered; copays range from $0–$75. The PAXCESS Co-Pay Savings Card provides up to $1,000 in annual savings.
• Medicare Part D: Covered, with the $2,000 annual out-of-pocket cap providing a ceiling.
• Uninsured/underinsured: The U.S. Government Patient Assistance Program (USG PAP) provides free Paxlovid to eligible patients (individual income <$46,950; couple income <$63,450).
• Prior authorization: Some plans require PA, which can delay treatment. Consider documenting high-risk criteria proactively in the prescription notes.

For patient-facing cost guidance, refer patients to our Paxlovid savings and assistance guide.

Tools and Resources for Providers

Several tools can help streamline Paxlovid prescribing and patient access:

• Medfinder for Providers: Real-time pharmacy availability search. Help patients identify which nearby pharmacies have the renal dose pack in stock before sending the prescription.
• Pfizer PAXCESS: Provider portal for patient enrollment in copay assistance and the USG PAP. Available at paxlovid.iassist.com.
• Liverpool COVID-19 Drug Interaction Checker: Free online tool for screening Paxlovid drug interactions (covid19-druginteractions.org).
• Telehealth platforms: For practices without same-day availability, telehealth services (Amazon One Medical, Doctor On Demand) can provide rapid evaluation and prescribing.

Looking Ahead

Key developments to watch in 2026 and beyond:

• Generic availability: No U.S. generic is available yet, though international generic manufacturing agreements exist through the Medicines Patent Pool for low- and middle-income countries.
• New antivirals in development: Several next-generation COVID-19 antivirals are in clinical trials, potentially offering fewer drug interactions and broader variant coverage.
• Updated COVID-19 treatment guidelines: NIH guidelines continue to evolve; stay current at covid19treatmentguidelines.nih.gov.

Final Thoughts

Prescribing Paxlovid 150 Mg /100 Mg Dose Pack requires attention beyond the clinical decision. The renal dose pack's limited pharmacy availability, the drug's extensive interaction profile, and cost barriers can all prevent patients from starting treatment within the critical window.

Proactive steps — screening interactions before prescribing, checking pharmacy availability through Medfinder, and connecting patients with financial assistance — can significantly improve treatment access. For a practical workflow guide, see our companion article: How to Help Your Patients Find Paxlovid in Stock.