Paxlovid Dosing with GFR 88 mL/min
Yes, a patient with a GFR of 88 mL/min can receive the standard Paxlovid dosing of 300 mg nirmatrelvir with 100 mg ritonavir twice daily for 5 days without any dose adjustment. 1
Renal Function Classification and Dosing
A GFR of 88 mL/min falls into the mild renal impairment category (eGFR ≥60 to <90 mL/min), which requires no dosage adjustment for Paxlovid. 1
Standard Dosing Regimen
- 300 mg nirmatrelvir (two 150 mg tablets) with 100 mg ritonavir (one 100 mg tablet)
- Administered twice daily for 5 days
- All three tablets taken together at approximately the same time each day
- Can be taken with or without food 1
Renal Dosing Algorithm
The FDA-approved dosing adjustments are based on eGFR thresholds: 1
- eGFR ≥60 mL/min (including your patient with GFR 88): Standard dose of 300/100 mg twice daily for 5 days
- eGFR ≥30 to <60 mL/min (moderate impairment): Reduced dose of 150/100 mg twice daily for 5 days
- eGFR <30 mL/min (severe impairment): Day 1: 300/100 mg once; Days 2-5: 150/100 mg once daily 1
Pharmacokinetic Rationale
Nirmatrelvir undergoes primarily renal elimination when co-administered with ritonavir, as ritonavir inhibits CYP3A4-mediated metabolism. 2 Population pharmacokinetic modeling demonstrates that nirmatrelvir clearance increases proportionally with creatinine clearance up to 70 mL/min/1.73 m², and remains independent above this threshold. 3
With a GFR of 88 mL/min, your patient is well above the 60 mL/min threshold where dose reduction becomes necessary, and nirmatrelvir exposure will remain within the therapeutic range without adjustment. 4
Clinical Evidence in Mild Renal Impairment
Studies show that patients with mild renal impairment (eGFR 60-89 mL/min) have only a 24% increase in nirmatrelvir exposure compared to those with normal renal function—this modest increase does not warrant dose adjustment and remains within safe therapeutic limits. 4 The standard dose maintains trough concentrations at 5.4× the EC90, providing adequate antiviral coverage without excessive drug accumulation. 2
Important Caveats
- Initiate treatment within 5 days of symptom onset for optimal efficacy 1
- Screen for drug-drug interactions before prescribing, as ritonavir is a potent CYP3A4 inhibitor that can cause significant interactions with many medications 5, 1
- Monitor renal function if the patient is on concomitant nephrotoxic medications or has fluctuating kidney function 1
- Ensure the patient is at high risk for progression to severe COVID-19 to meet indication criteria 1