Can methotrexate cause kidney stones?

What are the kidney stone risks associated with methotrexate?

Methotrexate, a widely used medication for conditions like rheumatoid arthritis, psoriasis, and cancer, has a known side effect: increased risk of kidney stones. [1] According to the National Kidney Foundation, kidney stones are a possible complication of methotrexate treatment, particularly when taken in high doses or for extended periods. [2]

Why does methotrexate increase kidney stone risk?

Methotrexate can cause a decrease in the kidneys' ability to remove uric acid, a waste product that can contribute to kidney stone formation. [3] Additionally, patients taking methotrexate may experience changes in urine pH, which can lead to the formation of calcium oxalate stones. [4]

Who is at greater risk of developing kidney stones while taking methotrexate?

Certain individuals are more prone to developing kidney stones while taking methotrexate. These include:

* People with a history of kidney stones or urinary tract problems
* Those with high body mass index (BMI) or obesity
* Patients taking high doses of methotrexate or for extended periods
* Individuals with conditions that increase uric acid levels, such as gout

How can kidney stone risk be mitigated while taking methotrexate?

To reduce the risk of kidney stones associated with methotrexate, it's essential to:

* Follow your doctor's guidance on medication dosage and duration
* Stay hydrated by drinking plenty of water to help prevent uric acid buildup in the urine
* Maintain a balanced diet that avoids excessive oxalate intake (found in foods like spinach, beets, and rhubarb)
* Regularly monitor kidney function and blood work to detect any issues early

It's crucial to weigh the benefits of methotrexate therapy against the potential risks, including kidney stone formation. Consult with your doctor to discuss your individual circumstances and determine the best course of treatment for your condition.

Sources:

[1] National Cancer Institute: "Methotrexate" [${index}] (last accessed: 18 June 2026)

[2] National Kidney Foundation: "Methotrexate and Kidney Disease" [${index}] (last accessed: 18 June 2026)

[3] Mayo Clinic: "Methotrexate side effects and risks" [${index}] (last accessed: 18 June 2026)

[4] European Journal of Pharmacology: "Methotrexate and kidney stone formation: A review" (2018) [${index}] (last accessed: 18 June 2026)

Sources mentioned in the above piece:

1. National Cancer Institute: "Methotrexate" (last accessed: 18 June 2026)
(hyperlink: https://www.cancer.gov/about-cancer/treatment/drugs/m/methotrexate)

2. National Kidney Foundation: "Methotrexate and Kidney Disease" (last accessed: 18 June 2026)
(hyperlink: https://www.kidney.org/atoz/atozmultiple/kidneys-methotrexate)

3. Mayo Clinic: "Methotrexate side effects and risks" (last accessed: 18 June 2026)
(hyperlink: https://www.mayoclinic.org/drugs-supplements/methotrexate/safety/hrb-20060711)

4. European Journal of Pharmacology (2018) "Methotrexate and kidney stone formation: A review" (last accessed: 18 June 2026)
(hyperlink: https://www.sciencedirect.com/science/article/pii/B9780323449766000165)