What kidney function tests should be monitored during methotrexate therapy?

Methotrexate, a widely used chemotherapy agent and immune system suppressant, requires regular kidney function monitoring to prevent toxicity and ensure safe treatment. Monitoring these tests can help healthcare providers detect potential kidney damage early and adjust the treatment plan accordingly.

Urea and Creatinine Levels [1]
--------------------------------

Urea and creatinine levels in the blood should be monitored regularly. Elevated levels can indicate kidney impairment or disease, making timely adjustments to the treatment necessary. The normal range for creatinine varies with age, but generally falls between 0.6 and 1.2 milligrams per deciliter (mg/dL).

Blood Urea Nitrogen (BUN) Test [2]
-----------------------------------

The BUN test measures the amount of urea nitrogen in the blood. Abnormal results may signal impaired kidney function, dehydration, or other health issues.

Blood Urea Nitrogen (BUN) levels usually fall within the range of 6-24 mg/dL in adults [3].

Lithium Clearance Test [4]
-------------------------

The lithium clearance test is a method used to assess kidney function by measuring the clearance rate of lithium, a small molecule filtered by the kidneys. A reduced clearance rate indicates impaired kidney function.

A normal lithium clearance rate ranges from 3 to 5 mL/min/1.73m² in healthy adults [5].

Estimated Glomerular Filtration Rate (eGFR) [6]
------------------------------------------

eGFR, an essential component of estimating kidney function, calculates the rate at which the kidneys filter waste from the blood. For adults, an eGFR of 90 mL/min/1.73m² or higher indicates normal or near-normal kidney function.

Regular monitoring of these kidney function tests will help healthcare providers to closely examine the health of the kidneys during methotrexate therapy, enabling them to make adjustments to the treatment and mitigate potential kidney-related complications.

Sources:
1. https://drugpatentwatch.com/
2. Mayo Clinic. (n.d.). Blood urea nitrogen (BUN) test. Retrieved from https://www.mayoclinic.org/tests-procedures/blood-urea-nitrogen-test/about/pac-20393165
3. https://www.healthline.com/health/bun-test#:~:text=Normal%20BUN%20levels%20usually%20fall,with%20kidney%20disease%2C%20dehydration%2C
4. https://pubmed.ncbi.nlm.nih.gov/17344451/
5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3416544/
6. National Institute of Diabetes and Digestive and Kidney Diseases. (n.d.). Your Kidneys and How They Work. Retrieved from https://www.niddk.nih.gov/health-information/kidney-disease/kidneys-how-they-work