Cidofovir and Methotrexate Interaction
Drug interaction information between Cidofovir and Methotrexate.
Cidofovir and Methotrexate have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Cidofovir and Methotrexate. This page displays the available source-record category and label text. The category is not an individual risk estimate or medication-combination direction.
How They Interact
Probenecid is required with cidofovir and can prevent the kidneys from clearing methotrexate from the body. This can cause methotrexate levels to rise, which may increase the risk of side effects.
FDA Label Information
Drug Interactions Probenecid Probenecid is known to interact with the metabolism or renal tubular excretion of many drugs (e.g., acetaminophen, acyclovir, angiotensin-converting enzyme inhibitors, aminosalicylic acid, barbiturates, benzodiazepines, bumetanide, clofibrate, methotrexate, famotidine, furosemide, nonsteroidal anti-inflammatory agents, theophylline, and zidovudine).
Cidofovir Also Interacts With
- Vancomycin major
- Gentamicin major
- Tobramycin major
- Amikacin major
- Amphotericin B major
Methotrexate Also Interacts With
- Celecoxib moderate
- Diflunisal moderate
- Indomethacin moderate
- Mefenamic Acid moderate
- Meloxicam moderate
Frequently Asked Questions
What SPL severity band is on file for Cidofovir + Methotrexate?
Compiled FDA labeling labels this pair minor. That is a source-record field, not an individual medication-combination decision.
Which drug in this pair has the larger labeled-interaction portfolio?
Methotrexate has 38 labeled pairs on file vs Cidofovir's 16. In the minor band specifically: Cidofovir has 11 (also Furosemide, Famotidine, Acetaminophen, Acyclovir); Methotrexate has 26 (also Aspirin, Folic Acid, Probenecid, Phenytoin).
What mechanism field is on file for Cidofovir and Methotrexate?
Probenecid is required with cidofovir and can prevent the kidneys from clearing methotrexate from the body. This can cause methotrexate levels to rise, which may increase the risk of side effects.
Cidofovir carries more major-labeled pairs than Methotrexate
SPL source-record counts only. This page's band is minor · classes on file: Cidofovir (Antiviral (Nucleotide Analog)); Methotrexate (Disease-Modifying Antirheumatic Drug (DMARD)).
Cidofovir has 5 major-labeled pairs vs Methotrexate's 0. This page itself is in the minor band, not the major band.
5 major · 0 moderate · 11 minor · 16 total
- Other minor peers for Cidofovir
- Furosemide
- Famotidine
- Acetaminophen
- Acyclovir
0 major · 12 moderate · 26 minor · 38 total
- Other minor peers for Methotrexate
- Aspirin
- Folic Acid
- Probenecid
- Phenytoin
Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. This registry does not provide individual medication-combination directions.
Read our methodology - how this data is sourced, computed, and verified.