Methotrexate

Cancer: The dose of methotrexate varies depending on the type of cancer being treated and body weight or size. Your doctor may recommend either the tablet or injectable form of Methotrexate.

If your doctor recommends the injectable form of methotrexate, the appropriate dose is usually injected one or more times weekly, either in cycles (i.e., some weeks no injections are given) or on a regular basis, depending on the type of cancer being treated. The tablet form of the medication can be given twice a week or daily, depending on the type of cancer being treated.

Rheumatoid arthritis: The usual adult dose of methotrexate is 7.5 mg taken as one dose once weekly by mouth or 2.5 mg taken every 12 hours for 3 doses once weekly. Doses are sometimes adjusted gradually according to response but are usually no more than 20 mg weekly. The benefits of treatment usually appear about 3 to 6 weeks after starting the medication.

Psoriasis: The usual adult starting dose of methotrexate is 10 mg to 25 mg per week in one dose (tablet or injection) or 2.5 mg (tablet) to 5 mg taken every 12 hours for 3 doses once weekly. Doses can be adjusted gradually but are usually no more than 30 mg weekly.

Methotrexate tablets may be taken with or without food. Your doctor may want you to drink extra fluids while you are taking Methotrexate in order to help pass the drug from the body and to prevent kidney problems.

Many things can affect the dose of medication that a person needs, such as age, body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor because there may be specific reasons why it is different.

It is important to take Methotrexate exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible and contact your doctor for advice on when to take the next dose. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

If you miss an appointment to receive the injection form of Methotrexate, contact your doctor as soon as possible to reschedule your appointment.

Store Methotrexate at room temperature, protect it from light and moisture, and keep it out of the reach of children.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

In addition to its desired action, this medication may cause some adverse effects, notably: it may cause mouth irritation and sores; it may decrease your appetite; it may cause diarrhea; it may cause nausea and vomiting; it may make your skin more sensitive to UV rays (e.g., sunlight, tanning lamps) - avoid exposure to UV rays as much as possible and protect yourself when out in the sun. Each person may react differently to a treatment. If you think this medication may be causing adverse effects (including those described here, or others), talk to your health care professional. He or she can help you to determine whether or not the medication is the source of the problem.

Tablets

Each capsule-shaped, yellow, scored tablet engraved "M 10" contains 10 mg of methotrexate. Nonmedicinal ingredients: maize starch, lactose monohydrate, magnesium stearate, polysorbate 80, microcrystalline cellulose, and Prejel PA 5 (pregelatinized starch). Methotrexate does not contain preservatives or colouring agents.

Injectable solution

10 mg/mL solution
Each mL of sterile, unpreserved isotonic solution contains methotrexate sodium equivalent to 10 mg of methotrexate. Nonmedicinal ingredients: sodium chloride 7.0 mg/mL, with sodium hydroxide and hydrochloric acid as pH adjusters.

25 mg/mL solution
Each mL of sterile, unpreserved, isotonic solution contains methotrexate sodium equivalent to 25 mg of methotrexate. Nonmedicinal ingredients: sodium chloride 2.6 mg/mL, with sodium hydroxide and hydrochloric acid as pH adjusters.

25 mg/mL solution (preserved)
Each mL of sterile, preserved, isotonic solution contains methotrexate sodium equivalent to 25 mg of methotrexate. Nonmedicinal ingredients: sodium chloride 2.6 mg/mL and 0.9% w/v benzyl alcohol (preserved), with sodium hydroxide and hydrochloric acid as pH adjusters.

Do not use Methotrexate if you:

• are allergic to methotrexate or any ingredients of Methotrexate
• have severely decreased renal function
• are breast-feeding
• are pregnant

Additionally, do not use Methotrexate for rheumatoid arthritis or psoriasis if you:

• have a history of alcohol abuse or alcoholic liver disease
• have chronic (long-term) liver disease
• have an immunodeficiency syndrome (e.g., HIV)
• have Anemia or other blood diseases
• are pregnant or are planning on becoming pregnant, or your partner is
• are going to be receiving nitrous oxide anaesthesia

There may be an interaction between methotrexate and any of the following:

• acitretin
• alcohol
• Alitretinoin
• aminoglycosides (e.g., gentamicin, tobramycin)
• Amiodarone
• amphotericin B
• Azathioprine
• "azole" antifungals (e.g., itraconazole, ketoconazole, Voriconazole)
• Baricitinib
• Carbamazepine
• Carvedilol
• Celecoxib
• chloral hydrate
• Cholestyramine
• ciprofloxacin
• Clozapine
• Colesevelam
• Colestipol
• Cyclosporine
• daclatasvir
• Deferiprone
• Denosumab
• Dexamethasone
• Dronedarone
• echinacea
• Eltrombopag
• Fingolimod
• folic acid
• foscarnet
• Furosemide
• Gemfibrozil
• HIV protease inhibitors (e.g., atazanavir, indinavir, ritonavir, saquinavir)
• Leflunomide
• Levetiracetam
• live vaccines (e.g., BCG, yellow fever, measles, mumps, rubella)
• macrolide antibiotics (e.g., clarithromycin, erythromycin)
• Mefloquine
• nonsteroidal anti-inflammatory medications (NSAIDs; e.g., Diclofenac, Ibuprofen, Ketoprofen, Naproxen)
• Ocrelizumab
• other cancer medications (e.g., Cytarabine, Doxorubicin, Vinblastine)
• penicillins (e.g., amoxicillin, ampicillin, penicillin, cloxacillin)
• Phenobarbital
• Phenytoin
• Pimecrolimus
• protein kinase inhibitors (e.g., Lapatinib, Nilotinib, Sunitinib)
• proton pump inhibitors (e.g., Lansoprazole, Omeprazole)
• quinidine
• quinine
• retinoids (e.g., tretinoin, retinol)
• rifampin
• Roflumilast
• St. John's wort
• salicylates (e.g., Asa, salsalate)
• sulfonamide antibiotics (e.g., Sulfasalazine, sulfamethoxazole, sulfadiazine)
• sulfasalazine
• Tacrolimus
• tegafur
• tenofovir
• Teriflunomide
• tetracyclines (e.g., doxycycline, Minocycline, Tetracycline)
• theophyllines (e.g., Aminophylline, Oxtriphylline, Theophylline)
• Tolvaptan
• Trazodone
• Trimethoprim
• vancomycin
• velpatasvir
• Verapamil
• Warfarin

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with Methotrexate. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the Nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or Allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use Methotrexate.

Anemia: Methotrexate may cause low levels of red blood cells. If you experience symptoms of reduced red blood cell count (anemia) such as shortness of breath, feeling unusually tired, or pale skin, contact your doctor as soon as possible.

Bleeding: Methotrexate may cause a reduced number of platelets in the blood, which can make it difficult to stop cuts from bleeding. If you notice any signs of bleeding, such as frequent nosebleeds, unexplained bruising, or black and tarry stools, notify your doctor as soon as possible. Your doctor will order routine blood tests to make sure potential problems are caught early.

Blood counts: Methotrexate can cause a decrease in the number of white blood cells, red blood cells, and platelets in your blood, especially when higher doses are used to treat cancer. This may increase your risk of bleeding or infections. Your doctor will monitor your blood counts with regular blood tests.

If you are using Methotrexate to treat cancer and already have a blood disorder such as anemia, reduced white blood cell counts, or reduced platelet counts, discuss with your doctor how Methotrexate may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Methotrexate, and whether any special monitoring is needed.

Cancer: Methotrexate may cause lymphoma (cancer of the immune cells) that may resolve when the medication is stopped. Your doctor will monitor for this.

Dizziness/fatigue: Methotrexate may cause dizziness and fatigue. Do not drive or operate machinery until you are certain that taking Methotrexate does not impair your ability to safely perform these tasks.

Hepatitis B and C infection: Methotrexate can cause reactivation of hepatitis B and C infections or worsening of existing infections. If you have a history of infection with hepatitis B or C virus, let your doctor know before starting Methotrexate.

Infection: As well as killing cancer cells, methotrexate can reduce the number of cells that fight infection in the body (white blood cells). If possible, avoid contact with people with contagious infections. Tell your doctor immediately if you notice signs of an infection, such as fever or chills, severe diarrhea, shortness of breath, prolonged dizziness, headache, stiff neck, weight loss, or listlessness.

If you are using Methotrexate to treat rheumatoid arthritis and have an infection, talk to your doctor about whether you need to temporarily stop Methotrexate until the infection resolves.

Kidney function: Reduced kidney function or Kidney Disease may cause Methotrexate to build up in the body. If you have reduced kidney function, discuss with your doctor how Methotrexate may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Methotrexate, and whether any special monitoring is needed. If you are using Methotrexate to treat cancer, your doctor may want you to drink extra fluids to help prevent kidney problems.

Liver problems: Methotrexate can cause liver problems. Your doctor will check your liver function with blood tests before starting Methotrexate and regularly during treatment. If you have liver problems or reduced liver function, discuss with your doctor how Methotrexate may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Methotrexate, and whether any special monitoring is needed. Do not drink alcohol while you are taking Methotrexate as this can increase the chance of liver problems.

If you experience symptoms of liver problems such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.

Lung problems: Lung inflammation (interstitial lung disease), causing difficulty breathing has occurred in some people taking Methotrexate. This complication can be serious and sometimes fatal. If you experience new or worsening shortness of breath or non-productive cough (with or without fever) at any time while you are taking methotrexate, contact your doctor immediately.

Nausea: Methotrexate may sometimes cause nausea. If you feel ill after taking methotrexate, do not stop taking the medication without first talking with your doctor. Your doctor or pharmacist may be able to help you with ways to reduce the nausea associated with taking Methotrexate.

Stomach and intestinal problems: If you have stomach or intestinal ulcers or Ulcerative Colitis, discuss with your doctor how Methotrexate may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Methotrexate, and whether any special monitoring is needed.

Seizures: Methotrexate has been reported to cause a condition called leukoencephalopathy that often causes seizures. Leukoencephalopathy is a rare disorder that causes nerve damage in the brain. Other symptoms of this disorder include memory loss, vision loss, trouble thinking, or difficulty walking. If you experience any of these, contact your doctor immediately.

Sun sensitivity: You may be more sensitive to the sun while using Methotrexate. Avoid excessive sun exposure and do not use sunlamps or sun beds until you know how Methotrexate affects your skin.

Tumour lysis syndrome: Methotrexate, like many other cancer medications, causes many cancer cells to be suddenly killed when treatment is first started. This can overwhelm the body with waste products from the cells. As a result, the body may not be able to keep up with getting rid of all the waste. When this happens, you may experience nausea, shortness of breath, cloudy urine, or joint pain. This is called tumour lysis syndrome. Your doctor may prescribe medications to help your body get rid of the waste products. Make sure you understand how to use these medications and report any of these signs or symptoms to your doctor immediately.

Vaccines: Vaccines may be ineffective if given during treatment with methotrexate. Live virus vaccines (e.g., Smallpox, Measles, Mumps, rubella, Chickenpox, Shingles) are not recommended during treatment with methotrexate.

Pregnancy: There is a possibility of birth defects if either partner is using methotrexate at the time of conception. If it is used during pregnancy, methotrexate may also cause birth defects or harm the baby.

Effective birth control should be practiced if either partner is using Methotrexate, including for a period of time after the medication is stopped. Talk to your doctor about how long you should wait to become pregnant after you or your partner stop taking methotrexate. If you become pregnant while taking Methotrexate, contact your doctor immediately.

If you have rheumatoid arthritis or psoriasis, you should not use Methotrexate if you are pregnant. If you might be pregnant, do not start methotrexate until you know for sure that you are not pregnant.

Breast-feeding: Methotrexate passes into breast milk. Due to the potential for serious harm to a baby if they are exposed to Methotrexate, women who are using methotrexate should not breast-feed.

Children: Methotrexate has been used to treat cancer in children. Methotrexate has also been used under close supervision of a doctor to treat other conditions in children, although the safety and effectiveness have not been clearly determined. Methotrexate should not be used for infants less than 1 month old.

Seniors: If you are a senior, you may be more at risk of experiencing side effects (including serious ones) and your doctor will monitor you very closely while you are using Methotrexate.

This product must be injected under the skin (subcutaneously), according to the technique you were shown. Be sure to choose a different injection site each time. Dispose of used syringes and needles safely. Your pharmacist can tell you the best way to do this. This medication is typically used only once a week. However, your pharmacist may have suggested a different schedule that is more appropriate for you. Important: Follow the instructions on the label. Do not use more of this product, or more often, than prescribed. It is recommended to drink plenty of water while using this medication. If you drink alcohol, a moderate consumption is recommended. Talk to your health care professional to find out exactly how much alcohol you can drink.