From the FDA Drug Label
• Dose reduction for moderate renal impairment (eGFR ≥30 to <60 mL/min): 150 mg nirmatrelvir (one 150 mg tablet) with 100 mg ritonavir (one 100 mg tablet), with both tablets taken together twice daily for 5 days. (2.3) • PAXLOVID is not recommended in patients with severe renal impairment (eGFR <30 mL/min). (2.3,8. 6)
For a 90-year-old patient with Covid and an eGFR of 61, the dose of Paxlovid is 300 mg nirmatrelvir (two 150 mg tablets) with 100 mg ritonavir (one 100 mg tablet), with all 3 tablets taken together twice daily for 5 days because the patient's eGFR is above 60 mL/min, which does not require a dose reduction 1.
From the Research
For a 90-year-old with COVID-19 and an eGFR of 61, the standard Paxlovid dose is appropriate: nirmatrelvir 300 mg (two 150 mg tablets) plus ritonavir 100 mg (one tablet) taken together twice daily for 5 days. This patient's kidney function, with an eGFR of 61 mL/min, falls within the normal to mildly reduced range, so no dose adjustment is needed, as supported by the study 2. Paxlovid should be started as soon as possible after diagnosis and within 5 days of symptom onset for maximum effectiveness, as shown in the study 3. The medication works by inhibiting viral replication, significantly reducing the risk of hospitalization and death in high-risk individuals, which includes elderly patients, as demonstrated in the study 3. Common side effects include altered taste, diarrhea, and potential drug interactions due to the ritonavir component. It's essential to review all current medications for potential interactions before starting Paxlovid, as ritonavir can affect the metabolism of many drugs, as noted in the study 3. The patient should complete the full 5-day course even if symptoms improve before completion. Given the patient's age and kidney function, it is crucial to monitor for potential adverse effects and adjust the treatment plan accordingly, considering the findings from the study 2. The use of Paxlovid in this patient is supported by the latest evidence, which highlights its effectiveness in reducing the risk of hospitalization and death in high-risk individuals, including those with mild kidney impairment, as shown in the study 2. Overall, the standard Paxlovid dose is recommended for this patient, with close monitoring and adjustment as needed to minimize potential risks and maximize benefits.