Methotrexate is an antifolate used in the treatment of cancer, various autoimmune diseases, and other conditions.

Methotrexate is commonly used as an effective chemotherapeutic agent in the treatment of cancers such as trophoblastic neoplasms, cancer of the breast, bladder, lung, head, and neck, leukemia, lymphoma, and osteosarcoma.

Another common use of methotrexate in low doses is the treatment of various autoimmune diseases, including, but not limited to:

• Sarcoidosis
• Lupus
• Psoriatic arthritis
• Psoriasis
• Crohn's disease
• Juvenile dermatomyositis
• Eczema
• Vasculitis
• Rheumatoid arthritis

It has also been used as an abortifacient, usually with misoprostol, to terminate early pregnancies.

Administering Methotrexate

Dosage is generally high when used to treat cancer and low to treat other conditions, such as autoimmune diseases, but dose is dependent upon many factors. There are numerous variables and conditions that influence dosage; it is not possible for us to summarize treatment for this medication.

That said, there are some unique functions of methotrexate that are not found among other medications. This one is particularly good at producing good results even with intermittent dosage. It is sometimes an experimental medication; used when other medications are not producing good results.

Methotrexate can also:

• Be given either orally or by injection.
• Demonstrated to have produced complete remission in multiple types of cancer.
• Slows or stops disease course in many autoimmune diseases.
• Improves pain, mobility, and stops bone destruction in rheumatoid arthritis.

A physician should always be contacted for proper evaluation, diagnosis, and dosage instructions. Always follow doctor instructions. In the event of overdose contact a physician or Poison Control Center immediately. Leucovorin is typically administered in the event of overdose to diminish toxicity.

Who Shouldn't take Methotrexate

Methotrexate should not be used by pregnant or nursing mothers, except as directed by a physician informed of their condition.

The medication should be used only with caution in patients with preexisting kidney or liver damage after comprehensive evaluation.

Patients with preexisting malignancy should be properly evaluated and diagnosed to ensure methotrexate is an appropriate therapy for their particular cancer type and progression.

Because methotrexate is typically used to treat only very serious and otherwise resistant diseases, it can be difficult to distinguish which side effects are a result of methotrexate therapy and which are developments of the underlying condition.

The most common side effects are:

• Nausea
• Gastric distress
• Leukopenia
• Ulcerative stomatitis
• Dizziness
• Fever
• Chills
• Reduced resistance to infection

Methotrexate has been associated with side effects in the following areas:

• Alimentary system
• Blood and lymphatic system
• Cardiovascular system
• Central nervous system
• Hepatic system
• Musculoskeletal system
• Ophthalmic system
• Pulmonary system
• Urogenital system
• Skin system

Other reactions include, but are not limited to, osteonecrosis, soft tissue necrosis, tumor lysis syndrome, reversible lymphoma, sudden death, loss of libido, diabetes, osteoporosis, vasculitis, arthralgia, myalgia, nodulosis, and tinnitus.

Patients receiving methotrexate therapy have sometimes developed fatal opportunistic infections most commonly associated with pneumocystic carinii pneumonia.

Incidents of allergy to methotrexate have been reported. If symptoms of methotrexate hypersensitivity are presented such as hives, itching, and swelling of the face or throat, contact a physician for immediate treatment.

The above list of potential side effects is not complete. Please consult the insert included with the medication for the most current and comprehensive list available.