Methotrexate is used to treat severe psoriasis, a condition which causes red, scaly patches to form on the skin that have not reacted well to other skin treatments. This drug is an antimetabolite, which helps to suppress the immune system and slow the growth of fast growing cells, so you may need to take care to avoid developing other conditions while using this medication. Use of this medication varies greatly from patient to patient, so you will need to work closely with a doctor to avoid side effects and dangerous reactions to your medication.
Indications and Usage
Methotrexate is sold under the names Rheumatrex and Trexall. Combination drugs or prescriptions in other countries may include the names Amethopterin an MTX. These drugs are mainly prescribed to treat psoriasis, but in some cases it has been prescribed to treat rheumatoid arthritis, certain types of cancer, including caner in the female reproductive system, lymphoma and leukemia. Methotrexate prescriptions are given in a tablet that is taken orally, but the schedule will be set for each individual patient. Make sure you have a clear set of instructions from your doctor before you begin to take Methotrexate so you do not inadvertently overdose on your medication.
It may take a few weeks before you begin to see results with Methotrexate. Do not stop taking your prescription if you feel you are not getting the results you need. If you are concerned about whether or not your body is reacting to your medication the way it should be, talk with your doctor about having your condition evaluated. They will inform you if an adjustment to your prescription is appropriate. Doses are more effective if you take them on your regular schedule. If you miss a dose, be sure to take it as soon as you remember, unless it is close to the point where you should take your next dose.
The size of your dose of methotrexate will vary based on what condition you are treating, the severity of your condition, and how your body responds to your initial prescription. You may be told to take your doses on a rotating schedule. If you are specifically told a set of instructions by your doctor that contradict those on the packaging, follow what your doctor says rather than this set of instructions.
Because dosage for Methotrexate varies so much for each patient, it is difficult to note a standard dose. In most cases, adults treating cancer with Methotrexate will take their doses every 24 hours for 4-6 weeks. You may be given 2 doses after a round of treatment for your disease. Patients are often given 2.5-3.3 mg, and those who are treating lymphoma are given 10-25 mg daily. Doses should not exceed 30 mg weekly.
Those treating psoriasis, or arthritis are often given 7.5 mg per week, or 2.5 mg in divided doses every 12 hours depending on the severity of their condition. Dosing adjustments will be made regularly depending on how the body reacts to the medication. Doses should not exceed 20 mg per week, especially in children treating juvenile rheumatoid arthritis.
Patients who are pregnant should not take Methotrexate. This drug is rated in pregnancy category X, which means it is extremely likely that damage to the fetus will occur. Those who suffer from liver disease or damage to the liver due to alcoholism may not be able to take Methotrexate due to the increased risk of liver failure. Talk with your doctor about how to adjust your dosage or eliminate Methotrexate from your schedule if you have or develop these conditions.
Methotrexate Side Effects
Common side effects of Methotrexate include dizziness, headache, drowsiness, decreased appetite, swollen or tender gums, reddened eyes and hair loss. These side effects usually cease as your body continues to become used to the medication. If your side effects do not stop or proceed to get worse, contact your doctor. You may need to adjust your dosage to make up for these side effects.
Up to 10 percent of patients have reported elevated liver function tests while using Methotrexate. These effects are often accompanied by vomiting. Other common side effects, occurring in 3-10 percent of users include stomatitis or thrombocytopenia. Talk with your doctor if you develop these side effects to determine whether or not you should continue taking this medication. If your symptoms become life threatening, contact emergency medical services for assistance.
If you begin to suffer from side effects including seizures, confusion, blurred vision, sudden loss of vision, weakness, difficulty moving one or both sides of your body, or loss of consciousness. These could be signs that you are developing a more serious condition or that you are having a negative reaction to Methotrexate. Contact emergency medical services immediately if you begin to suffer from any of these side effects. Have any information about your dosing schedule and how much Methotrexate you have taken recently ready when you make this call to assist this team in giving you adequate assistance.
Because Methotrexate suppresses the immune system, patients may be at risk for developing infections including pneumocystis carinii pneumonia, sepsis nocardiosis, histoplasmosis, cryptococcosis, herpes, and hepatitis. Talk with your doctor about this risk so that you can do what you can to help avoid these conditions. You may need to avoid certain activities or situations in order to prevent contracting these diseases.
When treating psoriasis, you may experience rashes, photosensitivity, pigmentary changes, alopecia, ecchymosis, acne or toxic epidermal necrolysis. These conditions will vary in severity based on your skin type. If you are prone to these conditions, talk with your doctor before starting Methotrexate before you start your prescription. Ask your doctor about any medications you should avoid using on your skin while taking Methotrexate to help avoid a negative reaction.
Drugs known to interact with Methotrexate include azathioprine, chloramphenicol, hydroxychloroquine, retinon, steroids, sulfa based drugs, phenytoin, probenecid, tetracycline, theophylline, gold treatments, oral diabetes medication, penicillin based antibiotics, medications used to reduce stomach acid and NSAIDS. Inform your doctor about any medications you are taking, especially those which may contain aspirin or folic acid to avoid a potential negative reaction to your medication.
Exposure to UV rays may be dangerous while you are taking Methotrexate because your skin will become more sensitive and you may be more susceptible to sunburn. Be sure to increase your use of sun protection while on this medication. You should not drink alcohol while on Methotrexate due to the increased risk of liver damage.