Methotrexate is a medication used to manage various conditions, including certain autoimmune diseases and cancers. It functions as an immunosuppressant, reducing inflammation and immune system activity, or as a chemotherapy agent, slowing cell growth. Proper administration of methotrexate, particularly regarding its timing, is important for its effectiveness and to minimize potential side effects. Understanding its correct administration is essential for individuals prescribed it.
Understanding Your Methotrexate Schedule
For individuals with chronic inflammatory conditions like rheumatoid arthritis, psoriatic arthritis, or severe psoriasis, methotrexate is prescribed to be taken once a week. This weekly schedule is important for safety, as taking the medication more frequently than directed can lead to serious side effects. The once-weekly regimen allows the body time to process the drug and recover before the next dose.
Methotrexate is available in both oral tablet and injectable forms. Injectable solutions, administered subcutaneously (under the skin) or intramuscularly (into the muscle), are also used. Injections may offer better absorption and fewer gastrointestinal side effects for some patients, especially at higher doses, because they bypass the digestive tract. The choice of form often depends on individual patient needs, preference, and how well the oral form is tolerated or absorbed.
Methotrexate dosing for certain cancers is different, often involving higher, more frequent, or daily doses managed by oncology specialists in a hospital setting. The information discussed here pertains to the once-weekly dosing regimen used for chronic inflammatory conditions.
Key Considerations for Dosing Timing
When taking methotrexate, consistency is important. It should be taken on the same day each week to maintain stable medication levels in the body and reduce the risk of toxicity. Many patients find it helpful to choose a specific day and stick to it, often aided by reminder systems or patient cards.
Regarding the time of day, consistency remains the most important factor, whether it is taken in the morning or evening. Some individuals prefer taking their dose in the evening to sleep through any initial side effects, such as nausea or fatigue, that can occur. Methotrexate can be taken with or without food, but taking it after meals may help reduce stomach upset.
Folic acid supplementation is prescribed alongside methotrexate to help reduce some side effects, such as mouth sores and gastrointestinal issues. Take folic acid on a different day from the methotrexate dose, typically at least 12 to 24 hours apart. Taking them on the same day can reduce the effectiveness of methotrexate.
If a weekly dose of methotrexate is missed, take it as soon as it is remembered, provided it is within one or two days of the scheduled time. If more than two days have passed, it is advised to skip the missed dose and take the next scheduled dose on the usual day. Never take a double dose to make up for a missed one, as this can lead to serious side effects. Patients who miss more than two consecutive doses should contact their healthcare provider for guidance.
Certain substances and medications can interact with methotrexate, affecting its levels or increasing side effects. Alcohol should be avoided or significantly limited due to increased risk of liver damage. Nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or naproxen, and some antibiotics (e.g., penicillins, sulfamethoxazole/trimethoprim) can reduce the body’s ability to clear methotrexate, leading to higher levels and increased toxicity. Discuss all medications, including over-the-counter drugs and supplements, with a healthcare provider for safe use with methotrexate.
Managing Side Effects and Monitoring
Methotrexate can cause various side effects. Common short-term effects include nausea, fatigue, mouth sores, and occasional hair thinning. These can be managed by taking folic acid, consuming the medication with food, or with anti-nausea medications. If side effects persist or become bothersome, a healthcare provider may suggest splitting the dose over 12 hours on the dosing day or switching to an injectable form.
Regular monitoring is an important part of treatment. Healthcare providers will order periodic blood tests, including complete blood counts (CBC) to check blood cell levels, and liver and kidney function tests. These tests help detect long-term side effects, such as changes in liver enzymes or kidney function, and allow for timely adjustments to the medication regimen. Initially, monitoring may be more frequent (e.g., every two weeks for six weeks), then transitioning to monthly or quarterly once the dose is stable and results are normal.
Patients should contact their doctor immediately if they experience signs of a serious reaction or infection, such as:
Fever
Chills
Persistent sore throat
Unexplained bruising or bleeding
Severe or persistent nausea, vomiting, or diarrhea
Mouth sores
Yellowing of the skin or eyes
Difficulty breathing
Unusual skin rashes
Also discuss vaccination plans with a healthcare provider, as some vaccines may not be safe while on immunosuppressive therapy. Methotrexate can cause birth defects, so effective contraception is necessary for both men and women during treatment and for a specified period after discontinuation.