Methotrexate: Uses and Adverse Effects

• Methotrexate is a conventional synthetic nonbiologic DMARD (traditional).

Therapeutic Use

• Decreases joint inflammation and subsequent joint damage.

Adverse Drug Reactions

• Bone marrow suppression (decreased platelets, red and white blood cells) is an adverse effect.
• Increased risk of infection.
• Liver damage.
• Gastrointestinal ulceration.
• Pulmonary fibrosis.
• Dizziness and headache.
• Nausea and vomiting.

Interventions

• Monitor for decreased platelets, red and white blood cell counts.
• Monitor for manifestations of infection.
• Monitor liver function tests and observe for jaundice.
• Monitor for gastrointestinal bleeding with methotrexate.
• Monitor for respiratory distress and decreased oxygenation.
• Monitor for abdominal pain, diarrhea, nausea, and vomiting.

Administration

• Administer methotrexate once a week via prescribed route (oral, subcutaneous, or intramuscular).
• Prescribing a folic acid supplement may decrease risk of toxicity.

Client Instructions

• Immediately report abnormal bleeding, bruising, or petechiae (pinpoint areas of blood under the skin).
• Immediately report ulcerations of the mouth or tongue.
• Report manifestations of infection immediately.
• Avoid ingesting alcohol.
• Immediately report yellowing of the skin and eyes.
• Report blood in vomitus or stools.
• Report difficulty breathing or shortness of breath.
• Drink adequate amounts (2 L) of water daily to ensure excretion of medication.
• For clients of child-bearing age, follow advice of healthcare provider regarding contraception.
• Avoid breastfeeding while on this medication.

Contraindications

• Methotrexate is teratogenic.
• Liver insufficiency or hepatitis are contraindications.
• Renal insufficiency is a contraindication.

Precautions

• Peptic ulcer or ulcerative colitis.
• Active bacterial or viral infections.

Interactions

• Concurrent use of methotrexate and digoxin may reduce digoxin level.
• Concurrent use of methotrexate and NSAIDs, salicylates, and sulfonamides may cause toxicity.
• NSAIDs can be administered during the initial period until methotrexate has exhibited its therapeutic effect, and then they must be discontinued.
• Caffeine may reduce the effectiveness of methotrexate.
• Concurrent use of warfarin may increase the risk for bleeding.
• Alcohol may increase risk of hepatotoxicity.

Methotrexate is a DMARD that decreases joint inflammation, but it can cause bone marrow suppression, liver damage and GI ulceration. Monitor blood counts, liver function, and for GI bleeding. Administer once a week and consider folic acid supplementation.