Can Paxlovid (nirmatrelvir/ritonavir) cause hyperkalemia?

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Last updated: March 28, 2025View editorial policy

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From the Research

Paxlovid can cause hyperkalemia, particularly in patients with kidney disease or those taking medications that increase potassium levels, due to the ritonavir component inhibiting enzymes that metabolize medications affecting potassium levels. Paxlovid is a combination medication containing nirmatrelvir and ritonavir used to treat COVID-19. The ritonavir component can inhibit certain enzymes in the liver that metabolize many medications, including some that affect potassium levels, as noted in a study on the pharmacokinetics of oral nirmatrelvir/ritonavir in subjects with renal impairment 1. This interaction can lead to increased potassium levels, particularly in patients with kidney disease, those taking medications that increase potassium (like ACE inhibitors, ARBs, potassium-sparing diuretics, or potassium supplements), or patients with conditions that predispose them to hyperkalemia.

Key Considerations

  • Patients starting Paxlovid should inform their healthcare provider about all medications they're taking to assess the risk of drug interactions, as highlighted in a study on the frequency, type, and severity of drug-related problems and pharmacist interventions in Paxlovid prescribing 2.
  • Those with kidney disease should have their kidney function and potassium levels monitored while on Paxlovid, as recommended in a study on the therapeutic effect of Paxlovid and Azvudine in the treatment of COVID-19 3.
  • Symptoms of hyperkalemia include muscle weakness, irregular heartbeat, and numbness or tingling, which should prompt immediate medical attention.
  • In some cases, medication adjustments may be necessary before starting Paxlovid to minimize this risk, as seen in a case report of a child with a kidney transplant who developed supratherapeutic tacrolimus levels after treatment with nirmatrelvir/ritonavir 4.

Monitoring and Precautions

  • Patients with renal impairment may require dose adjustments, as noted in a study on the pharmacokinetics of oral nirmatrelvir/ritonavir in subjects with renal impairment 1.
  • Healthcare providers should be cautious when prescribing nirmatrelvir/ritonavir to patients currently on medications that may interact with Paxlovid, such as tacrolimus, as highlighted in a case report on the interaction between nirmatrelvir/ritonavir and tacrolimus in a pediatric kidney transplant recipient 4.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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