Can a 77-year-old male with Impaired renal function (Chronic Kidney Disease, CKD), Hypertension (HTN), on atorvastatin (statin), doxazosin, ramipril, fenofibrate, allopurinol, and metoprolol, be treated with Paxlovid (nirmatrelvir/ritonavir) for COVID-19?

Paxlovid for a 77-Year-Old Male with COVID-19, CKD, and Multiple Medications

Yes, this patient can take Paxlovid with dose adjustment for his moderate renal impairment (eGFR 40 ml/min), but several of his medications need to be temporarily discontinued due to significant drug-drug interactions with ritonavir. 1

Paxlovid Dosing for Moderate Renal Impairment

For this patient with an eGFR of 40 ml/min (moderate renal impairment):

• Reduced dose: 150 mg nirmatrelvir (one tablet) with 100 mg ritonavir (one tablet) twice daily for 5 days 1
• Start treatment as soon as possible within 5 days of symptom onset

Medication Management During Paxlovid Treatment

Medications to Temporarily Discontinue:

1. Atorvastatin (statin):

   • Temporarily discontinue during the 5-day Paxlovid course
   • Ritonavir significantly increases statin levels, risking myopathy and rhabdomyolysis 2
   • Can safely pause statin for 5 days without significant cardiovascular risk

2. Fenofibrate:

   • Temporarily discontinue during Paxlovid treatment
   • Potential for increased exposure when combined with ritonavir 3
   • Short-term discontinuation poses minimal risk

Medications Requiring Dose Adjustment:

1. Ramipril (ACE inhibitor):
   • Continue but reduce dose by 50% during Paxlovid treatment
   • Monitor blood pressure closely
   • ACE inhibitors should be continued in patients with hypertension and COVID-19 4, 5

Medications That Can Be Continued Without Adjustment:

1. Doxazosin:

   • Can be continued at current dose
   • Minimal interaction with ritonavir

2. Metoprolol:

   • Can be continued at current dose
   • Monitor heart rate and blood pressure
   • Minimal CYP3A4 metabolism

3. Allopurinol:

   • Can be continued at current dose
   • No significant interaction with ritonavir

Monitoring Recommendations

1. Renal Function:

   • Monitor renal function during treatment
   • Adjust dose further if renal function worsens

2. Drug Interactions:

   • Watch for signs of toxicity from potential drug interactions
   • Monitor blood pressure closely due to ramipril dose adjustment

3. COVID-19 Symptoms:

   • Monitor for resolution of fever and improvement of respiratory symptoms 5

Important Considerations

• Timing: Start Paxlovid as soon as possible within 5 days of symptom onset for maximum benefit 1
• Complete Course: Ensure completion of the full 5-day treatment course to maximize viral clearance 1
• Medication Resumption: Resume temporarily discontinued medications 1 day after completing Paxlovid course

Common Pitfalls to Avoid

1. Not adjusting dose for renal impairment: This patient requires the reduced dose regimen due to moderate CKD
2. Missing significant drug interactions: Ritonavir is a potent CYP3A4 inhibitor that affects multiple medications
3. Discontinuing ACE inhibitors unnecessarily: Evidence supports continuing ACE inhibitors in COVID-19 patients with appropriate dose adjustment 4
4. Failing to monitor renal function: CKD patients may experience worsening renal function with COVID-19

Paxlovid remains beneficial for this high-risk patient (advanced age, CKD, hypertension) despite the need for medication adjustments, as it significantly reduces the risk of hospitalization and death from COVID-19 when started early in the disease course.