Methotrexate (MTX)

Oral administration is preferred for patients initiating methotrexate therapy. Subcutaneous administration may be considered in patients who are intolerant or have had inadequate response to oral methotrexate.

Subcutaneously administered MTX comes in vials that you must draw up your dose yourself in a syringe, allowing the administration of any specific dose prescribed for you. There are also pre-filled syringes with the common doses used for treatment already prepared in single-use syringes which may be easier to use and handle.

Persons involved with handling this drug should avoid contact with skin and inhalation of the airborne particles (avoid aerosolizing this medication). In the event of contamination, the affected area must be rinsed immediately with ample amounts of water. Pregnant or breastfeeding/chestfeeding healthcare providers or caregivers should not handle and/or administer MTX.

The most important thing to remember is that MTX is only taken once a week. Choose a day of the week that is least demanding since some people may feel unwell (tired, stomach upset, loss of appetite) for a day or two after taking MTX.

MTX comes in 2.5 and 10 mg tablets. The 2.5 mg tablets are more commonly used. If you are taking 15 mg or more a week (six or more 2.5 mg tablets), the dose can be split to take half in the morning and half at night (i.e., if you are taking six tablets a week, you can take three with breakfast and three with your evening meal). Dividing doses greater than 15 mg over the day allows for better absorption of your medication. MTX injections are available in a number of strengths. Typically, you will be given 0.3 to 1.0 mL per week.

Subcutaneously administered MTX comes in vials that you must draw up your dose yourself in a syringe, allowing the administration of any specific dose prescribed for you. There are also pre-filled syringes with the common doses used for treatment already prepared in single-use syringes which may be easier to use and handle.

To provide symptom relief while you are waiting for MTX to take effect, your prescriber may recommend taking a steroid, such as prednisone or a non-steroidal anti-inflammatory drug (NSAID).

Taking MTX can make it more difficult for your body to fight infections. If you have a fever or think you may have an infection, contact your healthcare provider. You may need to stop taking MTX if you are having surgery until you are healed and there is no sign of infection. Please discuss this with your prescriber.

Taking MTX before or during pregnancy can cause birth defects or even a miscarriage. Therefore, if you are pregnant or trying to get pregnant, both partners should refrain from taking this drug. The best time to stop MTX before getting pregnant, for both partners, is not entirely clear. Typically, it is recommended that both partners discontinue MTX for at least three months before pregnancy. If you or your partner are planning to get pregnant, please discuss this with your healthcare provider.

Anyone who has had a previous allergic reaction to MTX should avoid the medication. Any person who is breastfeeding/chest-feeding should also avoid MTX.

MTX interacts with a number of other medications, including some commonly used antibiotics. Please speak with your healthcare provider about whether any of the other medications you currently take interact with MTX. If you need an antibiotic while you are taking MTX, be sure to discuss this possible interaction with your prescriber and/or pharmacist.

You are encouraged to complete vaccinations prior to starting MTX therapy. For seasonal vaccinations (e.g., influenza, COVID-19), MTX may need to be held for one to two weeks afterwards to ensure maximum benefit from the vaccine. Talk to your healthcare provider to determine the best timeline to get vaccinated.

The most common side effects of MTX are nausea, feeling unwell or feeling tired for 24 to 48 hours after taking a dose. This usually improves over time as you get used to taking the medication. In some rare cases, people taking MTX may experience headaches, hair loss, mouth sores or ulcers and/or increased sensitivity to the sun.

MTX may affect your liver and blood counts. This should be closely monitored with routine blood work.

If you are administering MTX by subcutaneous injection, injection site reactions (redness, pain and itching) can occur. Talk to your healthcare provider if these symptoms become severe.

In rare occurrences, MTX may cause a serious lung problem. Please contact your healthcare provider if you develop shortness of breath or a new, prolonged cough while taking MTX.

To reduce some of the side effects, such as nausea and mouth sores, your prescriber will prescribe a folic acid supplement to be taken daily or a few times a week while you are taking MTX. Folic acid is generally taken on the days you are not administering MTX. Sometimes an increase in the folic acid dose or switching to another type of folic acid, called folinic acid, may help to reduce MTX related side effects.

Good oral hygiene also helps to prevent the development of mouth sores. Please speak with one of your healthcare providers if mouth sores become problematic.

Taking MTX before going to bed can sometimes help you sleep through any unpleasantness, such as nausea.

You may also notice that you are more sensitive to sun exposure while taking MTX, so be sure to use sunscreen regularly.

To avoid injection reactions, injection sites should be rotated, and injections should never be given into areas where the skin is tender, bruised, red and/or hard.

Restricting your intake of alcohol can also help avoid potential liver problems.

Your healthcare provider may meet with you regularly to ensure that MTX is adequately controlling your inflammatory arthritis and not causing any adverse effects.

Store multi-dose vials between 15°C and 25°C. After the vials are punctured, the vials should be stored between 2°C and 8°C for a maximum of four weeks (30 days). Protect from light and freezing.

Store pre-filled syringes between 15 to 25°C, away from heat and inside the outer packaging or carton to protect it from light.