Methotrexate

Common use

Methotrexate is an antimetabolite used to treat certain types of cancer. It inhibits dihydrofolate reductase, an important enzyme responsible for the synthesis of nucleotides for DNA. This medication inhibits synthesis of DNA, DNA reparation and cell mitosis. Cells of malignant tumor, bone marrow, embryonic cells, epithelial cells of the intestinal mucosa, bladder, oral cavity are the most sensitive to it.
Methotrexate is used in treatment of breast cancer, squamous cell carcinoma of the head and neck, lung cancer, trophoblastic tumor, cervical cancer, ovarian cancer, bladder cancer, colorectal cancer, esophagus cancer, stomach cancer, pancreatic cancer, testicular cancer, acute lymphoblastic leukemia and many others.

Dosage and direction

Take exactly as prescribed by your physician. Take Methotrexate orally with or without food. Do not chew or crush the tablet. To treat rheumatoid arthritis and psoriasis Methotrexate is taken weekly. Starting dose 7.5 mg of the medication once a week or 2.5 mg each twelve hours three times also once weekly. Treatment of cancer requires individual dosage and treatment only under control of your doctor.

Precautions

Caution should be exercised in the patients with ascites, dehydration, obstructive diseases of the digestive tract, pleural or peritoneal effusion, chronic renal failure, parasitic and infectious diseases of viral, fungal or bacterial origin due to the possible high risk of severe generalized disease development. Methotrexate toxicity increases in the individuals with herpes simplex, herpes zoster, chickenpox, measles, amoebiasis, strongyloidiasis (helminthosis caused by threadworm with allergic symptoms at the beginning of the disease), gout (also in history), infection and inflammation of mucosa in the mouth, nausea and vomiting (due to dehydration), stomach and duodenal ulcerations, ulcerative colitis, prior chemotherapy or radiotherapy, asthenia. When Metheotrexate is used to treat cancer cautiousness is need in the patients with aciduria (urine pH less than 7) and inhibited bone marrow hematopoiesis. Do not expose yourself to sun rays. Immunization by vaccines should be avoided for 3-12 months since the course of treatment with Methotrexate was finished. Men and women should use safe contraception as this drug is very toxic for an unborn baby.

Contraindications

This medicine cannot be administered to the patients with hypersensitivity to its components, immune deficiency, pregnant and breastfeeding women. When Methotrexate is used to treat patents with psoriasis or rheumatic diseases it cannot be used if they also have heavy suppression of bone marrow hematopoiesis, severe kidney or liver failure.

Possible side effect

Methotrexate is usually well tolerated but some patients may develop mouth sores, stomach upset, and low white blood counts. Methotrexate is known to be toxic to the liver, kidneys, lung and bone marrow. Blood tests should be done on a regular basis while treatment with this drug. Other adverse reactions may include headache, drowsiness and allergic reactions such as skin rash, itching, dizziness, and hair loss.

Drug interaction

Inform your doctor about all prescribed and over-the-counter medications, herbal products and food supplements you take and especially about NSAIDs such as ibuprofen (Motrin, Advil), diclofenac (Cataflam, Voltaren), naproxen (Aleve, Naprosyn), etodolac (Lodine), indomethacin (Indocin), meloxicam (Mobic), piroxicam (Feldene) as they increase Methotrexate toxicity); azathioprine (Imuran). Use of anti-gout drugs (allopurinol, colchicine, sulfinpirazon) requires correction of the dose. Inform your doctor also about chloramphenicol (Chloromycetin), hydroxychloroquine (Plaquenil, Quineprox), retinol, tretinoin (Retin-A), isotretinoin (Accutane), steroids (prednisone and others), sulfa drugs (Bactrim, Septra, Azulfidine), phenytoin (Dilantin), theophylline (Theobid, Theo-Dur, Elixophyllin, Slo-Bid), probenecid (Benemid), tetracycline (Brodspec, Panmycin, Sumycin, Tetracap), oral anti-diabetes drugs such as glipizide (Glucotrol), chlorpropamide (Diabinese), acetohexamide (Dymelor), glimepiride (Amaryl), or tolbutamide (Orinase), a penicillin antibiotics, salicylates (Dolobid, Salflex, Tricosal, Disalcid, Doan's Pills).

Missed dose

Consult your doctor if you miss a dose of this medicine.

Overdose

Contact your doctor immediately if you suspect overdose. Signs of overdose include nausea, vomiting, weakness, paleness, easy bruising or bleeding, mouth sores, black or bloody stools, coughing up blood, vomit similar to coffee grounds, decreased urination or anuria.

Storage

Store in a dry tight container away from sunlight at room temperature between 15-30 C (59-86 F) away from children and pets.

Disclaimer

We provide only general information about medications which does not cover all directions, possible drug integrations, or precautions. Information at the site cannot be used for self-treatment and self-diagnosis. Any specific instructions for a particular patient should be agreed with your health care adviser or doctor in charge of the case. We disclaim reliability of this information and mistakes it could contain. We are not responsible for any direct, indirect, special or other indirect damage as a result of any use of the information on this site and also for consequences of self-treatment.