Methotrexate – what it is, what it is for, how to take it and contraindications!
Methotrexate interferes with the growth of certain cells in the body, especially cells that reproduce rapidly, such as cancer cells, bone marrow cells, and skin cells.
Methotrexate is used to treat certain types of breast cancer , skin cancer , head and neck cancer, or lung cancer . It is also used to treat severe psoriasis and rheumatoid arthritis . Methotrexate is usually given after other drugs have been tried without successful treatment of symptoms.
Important information about methotrexate:
Methotrexate is usually not taken every day. You must use the correct dose for your condition. Some people have died after taking methotrexate every day by accident.
Do not use methotrexate to treat psoriasis or rheumatoid arthritis if you have low blood cell counts, a bone marrow disorder, liver disease (especially if caused by Alcoholism ), or if you are pregnant or breastfeeding.
Methotrexate can cause serious or potentially lethal side effects. Tell your doctor if you have Diarrhoea , mouth sores, cough , shortness of breath, stomach pain , dark urine, numbness or tingling, muscle weakness, confusion, seizures, or a rash that spreads and causes blisters and peeling.
Call your doctor if you have unusual bruising or bleeding, or signs of infection ( see Fever , Chills, Body Aches). Do not use methotrexate if you are pregnant or breastfeeding a baby.
Precautions before taking methotrexate:
You should not use methotrexate if you are allergic to it. Methotrexate should not be used to treat psoriasis or rheumatoid arthritis if you have:
- Alcoholism , Cirrhosis or chronic liver disease ;
- Low blood cell count;
- A weak immune system or bone marrow disorder;
- If you are pregnant or breastfeeding.
Methotrexate is sometimes used to treat cancer, even when patients have one of the conditions listed above. Your doctor will decide if this treatment is right for you.
Tell your doctor if you have:
- kidney disease ;
- Lung disease;
- Any type of infection;
- Radiation treatments.
Methotrexate can harm an unborn baby or cause birth defects, whether the mother or father is taking this medicine.
- If you are a woman, do not use methotrexate to treat psoriasis or rheumatoid arthritis if you are pregnant. You may need to have a negative pregnancy test before starting this treatment. Use an effective form of birth control while you are taking this medication and for 6 months after your last dose.
- If you are male, use a condom so as not to cause pregnancy while using methotrexate . Continue using condoms for at least 3 months after your last dose.
- Tell your doctor immediately if pregnancy occurs while the mother or father is taking methotrexate .
This medicine can affect fertility (ability to have children) in both men and women. However, it is important to use birth control to prevent pregnancy because methotrexate can harm the baby if pregnancy occurs.
You should not breast-feed while using this medicine. Do not give this medicine to a child without a doctor’s advice.
How should I take methotrexate?
Take methotrexate exactly as it was prescribed for you Follow all instructions on your prescription label and read all medication guides or instruction sheets.
Methotrexate is sometimes taken once or twice a week rather than every day. You must use the correct dose. Some people have died after taking methotrexate every day by accident. Ask your doctor or pharmacist if you are unsure about your dose or how often to take it.
Measure the liquid medicine carefully. Use the dosing syringe provided or use a medication dose measuring device (not a kitchen spoon).
Methotrexate can be toxic to organs and can lower blood cell counts. Your blood will need to be tested frequently, and you may need an occasional liver biopsy. Your cancer treatments may be delayed based on the results.
If you need to be sedated for dental work, tell your dentist that you are currently using this medication. Store tablets at room temperature away from moisture and heat.
Store the liquid remedy in the refrigerator, do not freeze. You can also store the liquid at room temperature for up to 60 days.
Dosage:
Usual Adult Dose for Acute Lymphoblastic Leukemia:
- Induction: 3.3 mg/m2/day orally or IM (in combination with prednisone 60 mg/m2).
- Maintenance (during remission): 15 mg/m2 IM or orally twice weekly.
- Alternating Remission Dosage: 2.5 mg/kg IV every 14 days.
Usual Adult Dose for Choriocarcinoma:
- 15 to 30 mg IM or orally daily for 5 days. Repeat courses 3 to 5 times with a rest period greater than or equal to 1 week between courses, until any overt symptoms of toxicity disappear.
- The effectiveness of therapy is typically assessed by 24-hour quantitative analysis of urinary chorionic gonadotropin (hCG), which will usually return to normal or less than 50 units/24 hours usually after the third or fourth course and usually followed by a measurable complete resolution. injuries in 4 to 6 weeks. One to two courses of methotrexate after hCG normalization is generally recommended.
Usual Adult Dose for Trophoblastic Disease:
- 15 to 30 mg IM or orally daily for 5 days. Repeat courses 3 to 5 times with a rest period greater than or equal to 1 week between courses, until any overt symptoms of toxicity disappear.
- The effectiveness of therapy is typically assessed by 24-hour quantitative analysis of urinary chorionic gonadotropin (hCG), which will usually return to normal or less than 50 units/24 hours usually after the third or fourth course and usually followed by a measurable complete resolution. injuries in 4 to 6 weeks. One to two courses of methotrexate after hCG normalization is generally recommended.
Usual Adult Dose of Methotrexate for Lymphoma:
- For Stage I-II Burkitt’s Tumor: 10 to 25 mg orally once daily for 4 to 8 days
- Stage III malignant lymphoma: 0.625 to 2.5 mg/kg orally daily as part of combination chemotherapy.
- Treatment at all stages usually consists of several courses of the drug interspersed with rest periods of 7 to 10 days.
Usual Adult Dose for Meningeal Leukemia:
- 12 mg/m2 intrathecally every 2 to 5 days until the CSF cell count returns to normal. At this point, an additional dose is advisable. Administration at intervals of less than 1 week may result in increased subacute toxicity.
Usual Adult Dose for Mycosis Fungoides:
- 2.5 to 10 mg PO daily or 50 mg IM once a week or 25 mg IM twice a week.
Usual Adult Dose for Osteosarcoma:
- Initial dose: 12 g/m 2 intravenously as a 4-hour infusion (in combination with other chemotherapeutic agents). If this dose is not adequate to reach a peak serum concentration of 1000 micromolar at the end of the infusion, the dose can be increased to 15 g/m2.
- Treatments can take place at 4, 5, 6, 7, 11, 12, 15, 16, 29, 30, 44, and 45 weeks after surgery.
- If the patient is vomiting or is unable to tolerate oral medication, leucovorin should be added to this regimen at the same dose and regimen as methotrexate .
Usual Adult Dose for Psoriasis:
- Single Dose: 10 to 25 mg/week orally, IM, or IV until adequate response is achieved.
- Split dose: 2.5 mg orally, IM or IV every 12 hours for 3 doses once a week.
- Maximum weekly dose: 30 mg.
Usual Adult Dose for Rheumatoid Arthritis:
- Single dose: 7.5 mg orally weekly.
- Split dose: 2.5 mg orally every 12 hours for 3 doses once a week.
- Maximum weekly dose: 20 mg.
Usual Adult Dose for Neoplastic Diseases:
- IV: Range is wide from 30-40 mg/m2/week to 100-12,000 mg/m2 with leucovorin rescue
Usual Pediatric Dose for Acute Lymphocytic Leukemia:
- 100 mg/m2 for 1 hour, followed by a 35-hour infusion, giving 900 mg/m2/day.
Usual Pediatric Dose for Dermatomyosite:
- 15 to 20 mg/m2 orally once a week.
Usual Pediatric Dose for Meningeal Leukemia:
- less than 4 months: 3 mg/dose intrathecally.
- greater than or equal to 4 months to less than 1 year: 6 mg/dose intrathecally.
- greater than or equal to 1 year to less than 2 years: 8 mg/dose intrathecally.
- greater than or equal to 2 years with less than 3 years: 10 mg/dose intrathecally.
- greater than or equal to 3 years: 12 mg/dose intrathecally.
The dose may be given every 2 to 5 days until the CSF count returns to normal, followed by a dose given once a week for 2 weeks and monthly thereafter. Administration at intervals of less than 1 week may result in increased subacute toxicity.
Usual Pediatric Dose for Neoplastic Diseases:
- 7.5 to 30 mg/m2 IM or orally every 2 weeks.
Alternative dosage: 10 to 18,000 mg/m2 IV bolus or continuous infusion over 6 to 42 hours.
Usual Pediatric Dose for Rheumatoid Arthritis:
- 5 to 15 mg/m2 IM or orally once a week.
- Usual Pediatric Dose for Solid Tumors:
- Less than 12 years: 12000 mg/m2 IV.
- Greater than or equal to 12 years: 8000 mg / m2 IV.
- Maximum dose: 18 grams.
What happens if I miss a dose of methotrexate?
Call your doctor for instructions if you miss a dose of methotrexate . Get your prescription refilled before you run out of medication completely.
What should I avoid while taking methotrexate?
Avoid drinking alcohol. It can increase the risk of liver damage. Do not receive a “live” vaccine while using methotrexate , or you could develop a serious infection. Live vaccines include measles , mumps , rubella (MMR), polio , rotavirus, typhoid fever , yellow fever , chickenpox ( chickenpox ), and zoster (shingles).
This medication may pass into body fluids (urine, stool, vomiting). Caregivers should wear rubber gloves while cleaning a patient’s bodily fluids, handling contaminated waste, washing clothes, or changing diapers. Wash your hands before and after removing gloves. Wash dirty clothes separately from other clothes.
Avoid exposure to sunlight or artificial UV rays (sun lamps or tanning beds), especially if you are being treated for psoriasis . Methotrexate can make your skin more sensitive to sunlight and your psoriasis can get worse.
Methotrexate side effects:
Get emergency medical help if you have signs of an allergic reaction to methotrexate (hives, difficulty breathing, swelling in your face or throat) or a severe skin reaction ( Fever , sore throat , burning eyes, skin pain, red or purple rash that spreads and causes blistering and peeling).
Call your doctor right away if you have:
- Fever , chills, swollen lymph glands, night sweats, weight loss;
- Vomiting, white patches or sores inside the mouth or on the lips;
- Diarrhea , blood in your urine or stool;
- Dry cough , coughing up mucus, chest pain, wheezing, shortness of breath;
- Convulsion (seizures);
- Kidney problems – little or no urination, swelling in the feet or ankles;
- Liver problems – stomach pain (upper right side), dark urine, jaundice (yellowing of the skin or eyes);
- Nervous problems – confusion, weakness, drowsiness, coordination problems, irritability, headache, neck stiffness, vision problems, loss of movement in any part of the body;
- Signs of tumor cell breakdown – confusion, tiredness, numbness or tingling, muscle cramps, muscle weakness, vomiting, diarrhea, fast or slow heart rate, seizures.
Side effects may be more likely in older adults.
Common methotrexate side effects can include:
- Fever , chills, tiredness, not feeling well;
- Canker sores ;
- Nausea , stomach pain;
- Dizziness;
- Abnormal liver function tests.
What other drugs will affect methotrexate?
Methotrexate can harm the liver, especially if you also use certain medications for infections, tuberculosis , depression , birth control, hormone replacement, high cholesterol, heart problems, high blood pressure, seizures, or medications for pain or arthritis (including acetaminophen, Tylenol, Advil, Motrin and Aleve).
Many medications can interact with methotrexate . This includes prescription and over-the-counter drugs, vitamins and herbal products. Not all possible interactions are listed here. Tell your doctor about all your current medications and any medications you start or stop using.
Other information:
Remember to keep this and all other medications out of the reach of children, never share your medications with others, and use methotrexate only for the indication prescribed.
Always consult your physician to ensure that the information displayed on this page applies to your personal circumstances.