Methotrexate (Rheumatrex, Trexall )  

Brand name: Rheumatrex^®, Trexall^TM  

Generic name:Methotrexate  

Other names: Amethopterin, MTX, Methotrexate Sodium  

Therapeutic Class: antimetabolite  

Manufacturer / Distributor:  Sanofi Aventis 

Availability: Methotrexate is available by prescription only 

Indications: Methotrexate is used to treat a variety of cancers, mainly:  

• leukemia 
• breast cancer 
• psoriasis 
• head and neck cancer
• lung cancer
• stomach cancer
• non-Hodgkin's lymphoma
• gestational trophoblastic cancer 
• esophageal cancer(cancer of theesophagus)
• osteosarcoma ( a common form of bone cancer)  
• Cutaneous T-cell lymphoma (also known as mycosis fungoides). 

Methotrexate is also used to treat certain non-cancerous conditions such as psoriasis, rheumatoid arthritis, polymyalgia rheumatica (PMR) and Crohn's disease. Talk to your doctor or pharmacist for more information.  

Dosage form: Methotrexate can be taken several ways:  

• by mouth, in pill form 
• intravenous infusion (into the vein IV) 
• intramuscular injection (into the muscle) 
• intraventricular infusion (within a ventricle) 
• Intrathecal infusion (inside the spinal canal). 

Dosage: Methotrexate comes as a tablet and injection. The form of treatment (pill or injection) and dosage prescribed by your doctor depends on several criteria: your health status, type of cancer being treated and its severity. In addition, you doctor will consider your body surface area (weight and height) and whether or not you are taking other drugs. In case you are prescribed injection, the treatment usually consists of injecting a dose of Methotrexate one or several times per week. The drug can be taken every few weeks, or on a regular basis, depending on the condition being treated.  

Your oncologist may recommend that you take Methotrexate by mouth. In this case, you will be prescribed an appropriate dosage capable of fighting the disease. It is important that you follow the instruction or the directions on the prescription label carefully. Take methotrexate and all drugs exactly as indicated by your health care provider. Do not change or stop the treatment without first consulting your doctor.  

Overdose: when methotrexate is given in hospital by professionals, the risk of overdose is almost nonexistent; however, accidental overdose or administrative mistake can happen. When the drug is taken by mouth chance of overdose increases. An overdose of methotrexate can cause a decrease in the number of blood cells in your bone marrow, which can lead to severe health problems and even death. Even in absence of therapeutic overdose, Methotrexate intoxication can lead to:  

• damage to the lining of the mouth, stomach or intestines 
• severe skin reactions 
• lung Infections such as pneumonia 
• bone and soft tissue damage 
• severe damage to the liver, kidney, lungs, and gastrointestinal tract 
• lymphoma, a cancer that rises in the lymphocytes of the immune system 
• Tumor lysis syndrome, a life-threatening complication of cancer treatment.  

If you experience any symptom (see methotrexate side effects below) that may indicate presence of these medical conditions, contact your physician or emergency clinic/hospital as soon as possible. Even in the absence of signs, it is important to see your doctor regularly during the treatment; do not neglect the appointments with your doctor and the laboratory.  

Missing dose: when methotrexate is given by injection, it is administered in hospital; missing dose is basically difficult if you keep all your doctor’s appointments. If for some reasons you cannot be present at the hospital for the treatment, contact your health care provider before the date scheduled for the injection.  

If you are recommended to take methotrexate by mouth in tablet form, it may happen you forget to take it. If you miss a dose, take it as soon as you remember it if it is not almost time to take the next dose. If you forgot to take the medicine, and it is almost time for the nest dose, wait for the next one; in any case, do not double the dose.  

Contraindications : Methotrexate is contraindicated or should be used with precaution in the following medical conditions : 

• alcohol consumption 
• excess fluid in the stomach area or around the lungs 
• low number of blood cells 
• kidney failure 
• liver failure 
• pregnancy 
• breast-feeding 
• allergy to methotrexate or any of its ingredients  
• allergy to antimetabolites in general  
• Elderly, infants or children should be treated with methotrexate only under medical supervision.

Mechanism of action (MOA): methotrexate is classified as an “antimetabolite”; it slows the proliferation of cancer cells by blocking DNA synthesis as well as regeneration and replication of cancer cells. 

Interactions: Some medicines may interact with methotrexate , and increase your risk of developing side effects. Talk you to your doctor before taking vitamins, nutritional supplements, and all nonsteroidal anti-inflammatory drugs (NSAID): aspirin, salsalate, choline magnesium trisalicylate (Tricosal, Trilisate), ibuprofen (Advil, Motrin), magnesium salicylate (Doan's), and naproxen (Aleve, Naprosyn). 

 In addition, talk to your doctor before taking thiazide diuretics, amoxicillin (Amoxil) and other penicillins, acitretin (Soriatane), azathioprine (Imuran), isotretinoin (Accutane), sulfasalazine (Azulfidine), or tretinoin (Vesanoid).  

Side effects: methotrexate not only attack cancer cells but also healthy cells, which often leads to, in most patients, the following side effects:  

• dry skin 
• itching 
• rash 
• acne 
• mouth sores
• weight loss 
• weakness 
• hair loss 
• decreased appetite 
• trouble sleeping
• Mild nausea and vomiting. 

If the side effects above persist for weeks, contact your oncologist. In addition, contact your doctor immediately if you experience symptoms that indicate:  

Damage to the liver, heart or lung: persistent nausea, extreme tiredness, pain in the upper right part of the stomach, dry cough, fast and irregular heartbeat, fever, shortness of breath or any flu-like symptom.  

Damage to the lining of the mouth, stomach or intestine: mouth sores, persistent diarrhea, black, tarry or bloody stools, sore throat, or bloody vomitting. 

Damage to the skin or bone: bone pain, fever, rash, blisters, peeling skin, yellowing of the skin or eyes, or purple, blue or black discoloration of the skin. 

Other problems : anxiety, depression, dehydration, nose bleeding, vision changes, red itchy eye, or intense headaches