How should I place an order in the patient chart for a confirmed COVID-19 patient to receive Paxlovid (nirmatrelvir/ritonavir)?

How to Order Paxlovid for Confirmed COVID-19 Patients

Order nirmatrelvir/ritonavir (Paxlovid) 300 mg/100 mg orally every 12 hours for 5 days, initiated within 5 days of symptom onset, after confirming the patient is at high or moderate risk for hospitalization and completing a mandatory drug interaction review. 1

Step-by-Step Ordering Algorithm

1. Confirm Eligibility Criteria

Before placing the order, verify:

• Laboratory-confirmed COVID-19 (positive test result) 2
• Symptom onset within 5 days - this is a hard cutoff 1
• Non-severe disease (patient does not require supplemental oxygen)
• High or moderate risk for progression to severe disease 3

2. Risk Stratification (Critical Step)

High-risk patients (strong recommendation for treatment) 3:

• Age ≥65 years
• Immunocompromised status
• Chronic kidney disease
• Diabetes
• Cardiovascular disease
• Chronic lung disease
• Cancer
• Obesity

Moderate-risk patients (conditional recommendation) 3:

• Partially vaccinated with 1+ risk factors
• Younger patients with multiple comorbidities

Do NOT order for low-risk patients (healthy, young, fully vaccinated without risk factors) 3

3. Mandatory Drug Interaction Review

This is the most critical safety step. Before ordering, you must:

• Review ALL current medications - ritonavir is a potent CYP3A4 inhibitor causing potentially life-threatening interactions 1
• Use the Liverpool COVID-19 Drug Interaction Tool (open-access online resource) 3
• Consider pharmacy consult if available - pharmacists identified significant interactions in 60-80% of cases 4, 5

Common problematic medications requiring management 5, 6:

• Immunosuppressants (tacrolimus, cyclosporine, sirolimus) - hold or reduce dose 7
• Statins (simvastatin, lovastatin) - hold during treatment
• Calcium channel blockers - may need dose adjustment
• Anticoagulants (rivaroxaban, apixaban) - monitor closely
• Antiarrhythmics (amiodarone) - contraindicated

If significant interactions cannot be managed, order molnupiravir instead 8, 9

4. Renal Function Assessment

Check estimated GFR before ordering:

• eGFR ≥60 mL/min: Standard dose (300 mg/100 mg twice daily)
• eGFR 30-59 mL/min: Reduced dose (150 mg/100 mg twice daily) 1
• eGFR <30 mL/min: NOT recommended (unless on hemodialysis - use 150 mg/100 mg once daily) 10

5. The Actual Order Entry

Order as written:

Nirmatrelvir 150 mg tablets - Take 2 tablets by mouth
WITH
Ritonavir 100 mg tablet - Take 1 tablet by mouth
TOGETHER every 12 hours for 5 days (total 30 nirmatrelvir tablets + 10 ritonavir tablets)

Start immediately. May take with or without food.

For renal dosing (eGFR 30-59):

Nirmatrelvir 150 mg tablet - Take 1 tablet by mouth
WITH
Ritonavir 100 mg tablet - Take 1 tablet by mouth
TOGETHER every 12 hours for 5 days (total 10 nirmatrelvir tablets + 10 ritonavir tablets)

6. Documentation Requirements in Chart

Document the following to justify the order:

• COVID-19 test result and date
• Date of symptom onset (must be ≤5 days)
• Risk factors for severe disease
• eGFR value
• Drug interaction review completed (list any medication adjustments made)
• Patient counseled on potential adverse effects (dysgeusia, diarrhea most common) 1

7. Contraindications (Do NOT Order If Present)

• Severe hepatic impairment (Child-Pugh Class C) 1
• Severe renal impairment (eGFR <30 mL/min, unless on hemodialysis) 1
• Unmanageable drug interactions with contraindicated medications 1
• Known hypersensitivity to nirmatrelvir or ritonavir 1

Common Pitfalls to Avoid

Timing errors: The 5-day window from symptom onset is absolute - treatment beyond this has no proven benefit 1

Skipping drug interaction review: This is the #1 cause of preventable harm. Ritonavir interactions persist for several days after completion 3, 6

Ordering for low-risk patients: This wastes limited resources and exposes patients to unnecessary drug interactions 3

Missing renal dose adjustment: Standard dosing in moderate renal impairment leads to drug accumulation 1

Forgetting to restart held medications: Document which medications were held and when to restart them (typically 3 days after last Paxlovid dose) 6

Special Populations

Pregnant/breastfeeding patients: May use Paxlovid - benefits outweigh theoretical risks 3

Vaccinated patients: Still benefit from treatment if high-risk 11

Immunocompromised patients: Particularly benefit from treatment but require careful drug interaction management 3

The evidence strongly supports Paxlovid as superior to molnupiravir (greater hospitalization reduction) and remdesivir (oral vs. IV administration) when drug interactions can be appropriately managed 3. Real-world data confirms 39% relative risk reduction in hospitalization and 61% reduction in death, with greatest absolute benefit in patients ≥65 years 11.