What laboratory tests are affected by Paxlovid (nirmatrelvir/ritonavir)?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: April 10, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the FDA Drug Label

The FDA drug label does not answer the question.

From the Research

Paxlovid can affect several laboratory test results during treatment, primarily impacting liver function tests, such as ALT and AST, as well as kidney function markers and blood glucose levels. The most recent and highest quality study, 1, published in 2025, provides valuable insights into the effects of Paxlovid on laboratory test results.

Key Laboratory Test Results Affected by Paxlovid

  • Liver function tests: Paxlovid may cause elevations in ALT (alanine aminotransferase) and AST (aspartate aminotransferase) 2
  • Kidney function markers: Increases in serum creatinine may occur without actual kidney injury due to Paxlovid's temporary inhibition of renal tubular secretion
  • Blood glucose levels: Paxlovid may alter blood glucose levels, particularly in diabetic patients, sometimes causing hypoglycemia that requires adjustment of diabetes medications
  • Coagulation parameters: Changes in prothrombin time and INR may occur, which is especially important for those on anticoagulant therapy These laboratory alterations are generally temporary and resolve after completing the standard 5-day Paxlovid course.

Monitoring Recommendations

Healthcare providers should monitor these values in patients with pre-existing liver or kidney disease, diabetes, or those on anticoagulants, but most patients don't require additional laboratory monitoring beyond what their underlying conditions would normally warrant 3. It is essential to note that the effects of Paxlovid on laboratory test results may vary depending on individual patient factors, such as age, comorbidities, and concomitant medications. Therefore, healthcare providers should exercise caution and carefully monitor patients receiving Paxlovid, especially those with underlying medical conditions.

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.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.