Contraindications of Folitrax (Methotrexate)
Methotrexate is absolutely contraindicated in pregnancy, nursing mothers, patients with cirrhosis, immunodeficiency syndromes, bone marrow dysfunction/failure, and severe renal or hepatic dysfunction. 1, 2
Absolute Contraindications
Pregnancy and breastfeeding
- Methotrexate is a known teratogen that can cause fetal death or congenital abnormalities
- Women of childbearing potential must use effective contraception during and for at least 3 months after therapy
- Men should avoid conception during and for at least 3 months after therapy
Severe organ dysfunction:
- Cirrhosis
- Severe hepatic dysfunction
- Severe renal dysfunction/patients on dialysis
- Pulmonary fibrosis or significantly reduced lung function
Hematologic conditions:
- Bone marrow hypoplasia, failure or dysfunction
- Significant leukopenia, thrombocytopenia, or anemia
- Preexisting blood dyscrasias
Immunologic conditions:
- Immunodeficiency syndromes
- Active infectious diseases (tuberculosis, untreated HIV)
Other:
- Hypersensitivity to methotrexate
- Active peptic ulceration
- Concurrent trimethoprim therapy 1
Relative Contraindications
- Mild to moderate renal impairment
- Mild to moderate liver dysfunction
- History of hepatitis B and C
- Gastritis
- Excessive alcohol consumption
- Patient unreliability (inability to comply with monitoring requirements)
- Recent live vaccinations
- Male partners of women wishing to conceive
- Obesity (BMI > 30)
- Diabetes mellitus
- Concomitant use of hepatotoxic drugs 1
Important Monitoring Considerations
When prescribing methotrexate, careful monitoring is essential to prevent serious adverse events:
Baseline laboratory tests should include:
- Complete blood count with differential
- Liver function tests (including albumin and bilirubin)
- Renal function tests
- Hepatitis B and C screening
Ongoing monitoring:
- Liver function tests every 3-6 months (more frequently if abnormalities develop)
- Complete blood count monitoring
- Renal function monitoring
Special Considerations
Alcohol
Patients should limit alcohol intake to well below national guidelines while taking methotrexate due to increased risk of hepatotoxicity. Many clinicians recommend complete abstinence, though a pragmatic approach may be reasonable for patients without other hepatic risk factors 1.
Pregnancy Prevention
Women must avoid pregnancy during treatment and for at least 3 months after discontinuation. Men should also avoid conception during treatment and for at least 3 months afterward 1, 2.
Drug Interactions
Several medications can increase methotrexate toxicity through various mechanisms:
- Salicylates and NSAIDs
- Sulfonamides
- Probenecid
- Penicillins
- Trimethoprim (absolute contraindication)
Folic Acid Supplementation
Folic acid supplementation (minimum 5 mg weekly) is strongly recommended to reduce the incidence of gastrointestinal and hepatic adverse effects without compromising treatment efficacy 1, 3.
By carefully screening patients for these contraindications and implementing appropriate monitoring, the risk of serious adverse events with methotrexate therapy can be significantly reduced while maintaining its therapeutic benefits.