Methotrexate (Oral)

Methotrexate belongs to a class of medicines known as antineoplastics, and treats several conditions such as cancer and arthritis by interfering with the growth of cancer cells and improving the immune system.

Overview

Methotrexate is a medicine used to treat various cancers such as breast, lung, blood, bone, head and neck as well as uterine cancer. It is also used to treat patients who have severe psoriasis, rheumatoid arthritis or polyarticular juvenile idiopathic arthritis, but whose conditions have not improved or responded to other forms of medication.

It belongs to a class of medicines known as antineoplastics and works by blocking an enzyme that cancer cells need in order to multiply and survive. This inhibits the growth and spread of cancer cells. Methotrexate also helps to suppress the immune system, for patients with psoriasis and arthritis. By treating arthritis early and aggressively, it is hoped that joint function is better preserved and that damage will be limited.

Conditions Treated

  • Various forms of cancer

Type Of Medicine

  • Antineoplastic

Side Effects

While using methotrexate, as with any other medication, patients may experience the development of side effects. Not all patients will encounter these side effects, which may range from mild to severe. However, if they do notice any unusual symptoms, they should contact their doctor right away.

There are some side effects that may happen while being treated with methotrexate that should go away within a short time. The patient may wish to consult with the doctor if they have any concerns and queries, or if the effects linger or become worse. They include:

  • Drowsiness

More serious side effects which require a doctor's attention as soon as possible include:

  • Sores on the lips or in the mouth

It is important for the patient to inform their doctor right away if they notice any of the above symptoms as they may include signs of problems such as anemia, liver problems or kidney problems. Methotrexate may also impact the patient's ability to fend off infections. Patients who experience signs such as chills, persistent coughs or sore throats and fevers, for example, should seek medical help as quickly as possible as this may be an indication of a serious infection.

As methotrexate can affect the production of sperm and therefore affect male fertility, patients who wish to start a family or continue having children should talk with their doctor to discuss the use of their medication and for more details.

If patients encounter the following serious side effects, they should get emergency medical treatment:

While it is rare for patients to develop a severe allergic reaction to methotrexate, it is still advisable to keep an eye out for the signs. If the patient experiences any of the following, they should get medical help immediately:

  • Rashes on skin

The above is not a complete list of all side effects that may occur. If patients notice any side effects that are not compiled here, they should talk to their doctor about them.

Dosage

Prior to taking methotrexate, patients should read all available information on the medicine from their doctor or pharmacist, and consult them about any questions or concerns they have. It is recommended to re-read the information before getting a refill if more medicine is required.

The dosage, strength of dose and dosing schedule are dependent on each individual patient's needs as well as their response to the treatment. As methotrexate is a strong medication and is also used in differing dosages for several different medical conditions, it is extremely important that patients stick closely to their prescription by the doctor and that they clarify all doubts before starting the medicine. Failure to adhere to the proper dosage may lead to serious side effects and even death.

The following is a guide to the average dose for each condition. Patients should not start, stop or alter the dose of their medication, or any other drug or supplement that they are currently consuming, without the knowledge and approval of their doctor. If they notice their prescribed dose is different from the average, they should talk to their doctor before changing their dosage. The length of time that a patient is required to take methotrexate will differ based on their condition and requirements.Taking more of the medicine or more often than has been prescribed will not hasten its effects and instead may increase the risk of side effects.

For cancer:

Adults- The doctor will determine the dose based on the patient's body size as well as the type of cancer that is being treated. An average dose consists of between 10 to 30 miligrams (mg) to be given once a day and may be given for several days before a resting period is required. After the resting period, the dose may be repeated. In certain conditions, 5 to 50mg to be given once a week may be prescribed instead. Dosage may be adjusted as required.

Children- The doctor will determine the dose based on the patient's body size as well as the type of cancer that is being treated. It is average for one dose to be given per day for several days, to be followed by a resting period. After this, the dosing cycle may be repeated. A dose of methotrexate may also be given once a week instead. Dosage may be adjusted during treatment as required.

For psoriasis:

Adults- Initial dosage may consist of 10 to 25mg to be given once a week, or 2.5mg spaced 12 hours apart for a total of 3 doses to be given once a week. A typical dose should not exceed 30mg per week. The doctor may adjust the dosage as required.

Children- The doctor will determine the use and dosage based on the patient's needs.

For rheumatoid arthritis and juvenile arthritis:

Adults- Initial dosage may consist of 7.5mg to be given once a week, or 2.5mg spaced 12 hours apart for a total of 3 doses to be given once a week. The doctor may adjust the dosage as required.

Children- The doctor will determine the use and dosage based on the patient's body size. Initial dose starts at 10mg per square meter of body size, to be given once a week. The doctor may adjust the dose as required.

Patients who are being treated with methotrexate for psoriasis or rheumatoid arthritis may need to continue taking this medicine for several months to receive the full benefit of the drug.

During treatment with methotrexate, patients should consume plenty of fluids to help removal of the drug via the kidneys. This will also help to alleviate or decrease the risk of unwanted side effects.

Pregnant or breastfeeding people should not handle methotrexate or breathe in the dust from the tablets as this drug can pass through skin and into the lungs, and harm both infants and unborn babies. If patients suspect they are pregnant or wish to become pregnant, they should talk to their doctor about their use of methotrexate.

Interactions

Drugs may interact with one another, supplements or various herbal products to produce unwanted effects, or even affect the efficiency of the medication. Patients should keep a list of drugs, supplements and other products they are or have consumed, so that they can share the list with their doctor in order to help prevent undesirable interactions. However, the doctor may on occasion prescribe drugs or supplements that are known to interact with methotrexate if they feel that the effects are needed and if the side effects do not outweigh the benefits.

The following is a non-exhaustive list of medications and supplements known to interact with methotrexate:

  • Acetaminophen

In general, patients should take note of drugs that reduce stomach acid, also known as proton pump inhibitors or PPIs, such as esomeprazole and pantoprazole as they may increase the amount of methotrexate in the patient's blood. This is especially important to note if the patient has been prescribed high doses of methotrexate as part of their treatment.

They should also take note of drugs that may lead to an increased chance of developing kidney and liver problems such as cisplatin, azathioprine, retinoids, penicillins, phenytoin and tetracyclines. The doctor will be able to advise the patient on the use or combinations of these medicines.

For a full list of medications, supplements and herbal products that interact with methotrexate, patients may wish to consult their doctor or pharmacist.

Aside from other medicines, certain medical conditions may also affect the way methotrexate works, or elevate the risk of unwanted side effects. Patients should let their doctors know about their medical history, especially if they have or have had:

  • Bacterial, fungal or viral infections

If the patient is undergoing vaccination, they should also be sure to inform their doctor as methotrexate is likely to interact with:

While being treated with methotrexate, patients should take note of certain foods or consumables that may interact with their medication. There is an increased chance of methotrexate interacting with alcohol, as the medicine may increase the risk of liver problems. Patients should also refrain from foods or drinks containing caffeine such as coffee or cola. If they have any questions regarding food, drink or tobacco, they should resolve these with their doctor prior to starting treatment.

Warnings

During treatment with methotrexate, it is important that patients show up for regular visits to the doctor in order to check on the patient's progress and response to the medication, and that it is working as intended. During these checks, blood tests may be required to ensure that no unwanted effects are developing.

Consuming alcohol and methotrexate may cause unwanted interactions. There may be a higher risk of liver problems, which can be detected by symptoms such as yellowing eyes or skin, nausea, vomiting, loss of appetite, dark urine, pale or clay colored stools or pain and tenderness in the stomach or abdominal area. Patients who encounter these effects should check with their doctor as soon as possible.

The use of methotrexate may lead to the development of certain problems, such as the lowering of white blood cell levels as well as platelets in the blood. These can, respectively, increase the chances of getting an infection (bacterial, viral or fungal) and make it difficult for blood to clot and therefore for the body to heal. Patients whose blood count become low should consider taking precautions against infections and unusual bleeding such as:

  • Avoiding people with infections. Patients should check with their doctor if they believe they have an infection, or if they experience the following: coughing or hoarseness of the voice, fevers, chills, pain in the side or lower back or difficulties or pain with urination.

During and after treatment with methotrexate, patients should not schedule any vaccines without first informing their doctor. This is because methotrexate can lower the patient's immunity and cause them to get the infection that the vaccine is supposed to prevent. Similarly, patients should take care to avoid people who are being vaccinated, or have been recently vaccinated, as there is a chance that they may get infected by the live vaccines. Some of these vaccines include ones for measles, influenza, poliovirus, rotavirus, mumps and rubella. If contact is unavoidable, patients should try not to stand too close to the other person, and leave the room as soon as possible.

Methotrexate may lead to a serious reaction known as tumor lysis syndrome. Symptoms of this syndrome can include unusual tiredness or weakness, swelling in the feet and lower legs, pain in the stomach, lower back, side and joints, feelings of stiffness, quick weight gain, and changes in the amount of urine. Patients who notice such symptoms should contact their doctor right away.

This medication can cause serious skin reactions to happen, which can lead to signs such as blisters on the skin, peeling or loosening skin, red lesions, rashes, sores and ulcers, acne as well as fever and chills. This is also a cause to seek medical attention.

For patients who are planning on having children, both men and women, they should talk to their doctor prior to starting methotrexate. It can cause infertility.

This medication can be absorbed into the skin and the lungs, and can harm unborn babies. Men who are being treated with methotrexate should use birth control during treatment, and also for at least 3 months after their last dose of the medicine, as it can cause birth defects if the father of the child is on methotrexate when his partner becomes pregnant. Women who are on methotrexate should use birth control for at least one subsequent menstrual cycle.

Patients who become pregnant or suspect that they are pregnant while using methotrexate should inform their doctors right away.

This medication should not be used in conjunction with other drugs, supplements or herbal products without a doctor's knowledge and consent.

Storage

Methotrexate should be stored in a closed container in a cool and dry place, kept away from sunlight or heat. It should not be exposed to freezing temperatures. The medication should not be kept in bathrooms as the levels of humidity may be too high.

Methotrexate should be kept out of reach of children and animals.

The medicine should be disposed of properly when it has expired or is no longer wanted. If the patient is unsure of how to handle medical waste, they can approach their doctor or local waste management for ways to discard their medication safely.

Summary

Methotrexate in its oral route is used to treat various health issues. These include various forms of cancer (such as breast, lung, blood, head and neck, bone and uterine), as well as cases of psoriasis, rheumatoid arthritis and polyarticular juvenile idiopathic arthritis which have not responded favorably to other treatments.

As it is a strong medication, patients are required to take the correct dosage and to follow their prescriptions closely as the wrong dosage may lead to severe side effects and in the worst scenario, even to death.

While an effective medicine, methotrexate does carry a chance of patients developing unwanted side effects and conditions such as liver problems, tumor lysis syndrome, increased risk of infections as well as skin reactions. Patients should check with their doctor for ways to alleviate the risk, as well as ensure that they attend regular check-ups to check that the medicine is working as intended and to catch any unwanted effects before they persist or become worse.

Methotrexate is likely to harm unborn babies, and can pass through skin and into the lungs. It is unadvised for patients to breastfeed while on this medication. Because of its risk to unborn babies, patients of either gender are advised to use reliable forms of birth control during treatment and for up to 3 months or a menstrual cycle after their last dose of this medication.

Links

 Methotrexate belongs to a class of medicines known as antineoplastics, and treats several conditions such as cancer and arthritis by interfering with the growth of cancer cells and improving the immune system.

  • Rheumatoid arthritis
  • Polyarticular juvenile idiopathic arthritis
  • Psoriasis
  • Dizziness
  • Pain in the stomach area
  • Nausea
  • Vomiting
  • Hair loss (hair growth should resume after the treatment ends)
  • Pain in the stomach or abdominal area
  • Diarrhea
  • Black tarry stools
  • Blood in vomit
  • Blood in urine or stools
  • Yellowing eyes or skin
  • Pain in joints
  • Back pain
  • Skin becoming reddened or discoloured
  • Pinpoint pricks of red appearing on skin
  • Feet or lower legs swelling
  • Blurred vision
  • Confusion
  • Dry coughing or hoarseness of the voice
  • Fever
  • Chills
  • Headaches
  • Difficulties with breathing
  • Unusual weakness or tiredness
  • Pale skin
  • Unusual bleeding or bruising
  • Pain or difficulty with urination
  • Bone pain
  • Feeling stiffness in neck
  • Changes in vision
  • Changes in mood or mental state
  • Seizures
  • Irregular heartbeat
  • Feeling weak on one side of the body
  • Itching
  • Swelling, especially of the face, tongue and throat
  • Feeling severely dizzy
  • Difficulties with breathing
  • Acitretin
  • Adalimumab
  • Amoxicillin
  • Asparaginase
  • Celecoxib
  • Chloramphenicol
  • Clindamycin
  • Duloxetine
  • Diclofenac
  • Esomeprazole
  • Etanercept
  • Fish oil (omega-3 polyunsaturated fatty acids
  • Folic acid
  • Hydroxychloroquine
  • Ibuprofen
  • Infliximab
  • Leflonomide
  • Leucovorin
  • Levothyroxine
  • Meloxicam
  • Prednisone
  • Pregabalin
  • Sulfamethoxazole/trimethoprim
  • Tramadol
  • Vitamin B12 (cyanocobalamin)
  • Vitamin D3 (cholecalciferol)
  • Liver disease
  • Kidney disease
  • Diabetes
  • Alcohol abuse
  • Ascites (excess fluid in the stomach area)
  • Pleural effusion (excess fluid in the lungs)
  • Anemia
  • Leukopenia (low levels of white blood cells)
  • Thrombocytopenia (low levels of platelet blood)
  • Weak immune systems
  • Ulcerative colitis (inflammation of the colon)
  • Peptic ulcers
  • Mumps virus vaccine (live)
  • Rotavirus vaccine (live)
  • Rubella virus vaccine (live)
  • Varicella virus vaccine
  • Taking care when brushing, flossing or using toothpicks as these can sometimes cause minor bleeding in the mouth. During treatment of methotrexate, the doctor (or a referred dentist) may recommend alternate ways of cleaning the teeth and gums. Patients should inform their doctors if they are planning to undergo any dental work, and let their dentists know that they are on methotrexate.
  • Being more careful with using sharp objects, such as razors, scissors, or nail clippers.
  • Refraining from contact sports or situations where injury or bruising is likely to happen such as dance or rock climbing.
  • Avoiding touching the inside of the nose or eyes unless the patient has just washed their hands and not touched anything else prior.
  • Consulting the doctor as quickly as possible if they notice unusual symptoms such as blood in the stools or urine or black and tarry stools, unusual bleeding or bruising, and pinpoint pricks of red appearing on their skin