Can a patient with impaired renal function (dialysis 3 days a week) take Paxlovid (nirmatrelvir/ritonavir) if taking atorvastatin, metoprolol, occasional diltiazem (as needed), and gabapentin?

Can This Patient Take Paxlovid?

No, this patient should not take Paxlovid due to severe renal impairment (dialysis 3 days/week) and significant drug-drug interactions with atorvastatin and diltiazem that create unacceptable safety risks. 1

Critical Contraindication: Severe Renal Impairment

Paxlovid is not recommended for patients with severe renal impairment (eGFR <30 mL/min) or end-stage renal disease receiving dialysis until more data are available. 1 The FDA label explicitly states that "the appropriate dosage for patients with severe renal impairment has not been determined" and that Paxlovid should not be used in patients with eGFR <30 mL/min or those receiving dialysis. 1

Why Dialysis Patients Are at Risk

• Nirmatrelvir is eliminated renally, and systemic exposure increases dramatically with renal impairment—patients with severe renal impairment showed a 304% increase in drug exposure compared to those with normal renal function. 2
• In a study of 122 patients prescribed Paxlovid, 3 patients (2.1%) received the drug despite severe renal impairment being a contraindication, highlighting this as a common prescribing error. 3
• Dialysis does not adequately remove nirmatrelvir, leading to drug accumulation and increased toxicity risk. 1, 2

Major Drug-Drug Interactions

Atorvastatin: Contraindicated Combination

Atorvastatin must be stopped during Paxlovid treatment due to severe interaction risk. 1 Ritonavir is a potent CYP3A4 inhibitor that dramatically increases statin levels, creating risk of rhabdomyolysis and acute kidney injury—particularly dangerous in a patient already on dialysis. 4

• The FDA label does not list atorvastatin as absolutely contraindicated (unlike simvastatin and lovastatin), but multiple case reports document severe toxicities with this combination. 4
• In patients requiring Paxlovid, atorvastatin should be held for the 5-day treatment course and for 2-3 days after completion. 4

Diltiazem: Significant Interaction

Diltiazem levels will increase substantially with Paxlovid, risking severe bradycardia, heart block, and hypotension. 4 Ritonavir inhibits CYP3A4, which is the primary metabolic pathway for diltiazem. 4

• Case reports document severe cardiovascular toxicity when calcium channel blockers are combined with ritonavir-containing regimens. 4
• Even "as needed" use creates risk if taken during the 5-day Paxlovid course. 4

Metoprolol: Moderate Interaction

Metoprolol levels may increase modestly through CYP2D6 inhibition by ritonavir, but this is generally manageable with monitoring for excessive bradycardia or hypotension. 4 This interaction alone would not preclude Paxlovid use if other factors were favorable.

Gabapentin: No Significant Interaction

Gabapentin is renally eliminated and does not undergo hepatic metabolism, so no interaction with Paxlovid is expected. 5 However, gabapentin dosing should already be adjusted for dialysis (typically 100-300 mg post-dialysis on dialysis days). 5

Clinical Decision Framework

When Paxlovid Cannot Be Used

A patient meets criteria for avoiding Paxlovid if ANY of the following apply:

• eGFR <30 mL/min or receiving dialysis 1
• Taking medications that cannot be safely held and have severe interactions (simvastatin, lovastatin, certain antiarrhythmics) 1
• Severe hepatic impairment (Child-Pugh Class C) 1

Alternative COVID-19 Treatment Options

For this high-risk dialysis patient with COVID-19:

• Remdesivir may be considered, though it also requires renal dose adjustment and has limited data in dialysis patients. 6
• Monoclonal antibodies (if available and active against circulating variants) do not have renal elimination concerns. 6
• Supportive care with close monitoring for disease progression remains essential. 6

Common Pitfalls to Avoid

• Do not attempt dose reduction of Paxlovid in dialysis patients—the FDA explicitly states no dosing recommendation exists for this population, and the 150/100 mg dose is only validated for moderate renal impairment (eGFR 30-60 mL/min). 1, 2
• Do not assume "as needed" medications are safe—diltiazem taken even once during Paxlovid therapy creates significant risk. 4
• Do not rely on dialysis to remove nirmatrelvir—conventional dialysis contributes minimally to drug clearance. 1, 2
• Pharmacist involvement is essential—in one study, 87.1% of Paxlovid prescriptions required intervention to prevent drug-related problems, with DDIs being the most common issue (57.1% of cases). 3