How to give methotrexate in psoriasis for effective management

Methotrexate has been a cornerstone in treating moderate-to-severe psoriasis for nearly 50 years, often prescribed when topical treatments and light therapy are insufficient. Administering methotrexate correctly is crucial for maximizing its benefits while minimizing potential side effects. This guide explains how to give methotrexate in psoriasis, covering oral and injectable methods, proper administration schedules, and essential safety measures.

Quick Summary

This resource provides comprehensive instructions on administering methotrexate for psoriasis, detailing the benefits and techniques for both oral and subcutaneous delivery. Key aspects include weekly administration schedules, the importance of folic acid supplementation, and essential safety monitoring to optimize treatment and manage potential adverse effects.

Key Points

• Weekly Administration is Crucial: Methotrexate for psoriasis is taken only once a week to avoid serious toxicity; never take it daily.

• Oral vs. Injectable Options: Methotrexate can be taken as an oral tablet or via subcutaneous injection, with the injectable form offering better bioavailability and fewer GI side effects at higher administered quantities.

• Always Use Folic Acid: A folic acid supplement is essential to take with methotrexate (on a different day) to reduce side effects like nausea and mouth sores without compromising the drug's effectiveness.

• Avoid Alcohol and Monitor Closely: Patients must abstain from alcohol due to increased risk of liver damage and undergo regular blood tests to monitor liver function, kidney function, and blood counts.

• Contraindicated in Pregnancy: Methotrexate is strictly forbidden for pregnant women and those planning to conceive (applies to both partners), due to the risk of birth defects.

• Self-Injection Technique: For subcutaneous injections, choose a clean site on the abdomen or thigh, avoid active plaques, and dispose of sharps properly.

Methotrexate administration for psoriasis

Methotrexate is a systemic treatment used for moderate-to-severe psoriasis that works by suppressing the overactive immune system responsible for the accelerated skin cell growth. It is most commonly prescribed as a once-weekly dose, not daily, to avoid serious toxicity. A healthcare provider will determine the appropriate dose and administration route for each patient, considering their condition's severity, overall health, and tolerance to the medication.

Oral administration: Tablets and liquids

The most common route for methotrexate is oral, typically in tablet form, which is often the first approach for many patients. Oral administration is convenient and doesn't require self-injection. However, it can cause gastrointestinal side effects like nausea or an upset stomach for some individuals.

Standard oral administration schedule:

• Once-weekly dose: The standard approach is to take the entire weekly dose in a single administration.
• Split administration: To minimize nausea and other gastrointestinal side effects, a doctor might prescribe the total weekly dose in two or three smaller portions, taken at intervals over a 24-36 hour period. This can improve tolerability, though patients must be vigilant to not accidentally take their medication daily.

Injectable (parenteral) administration

For patients who experience significant gastrointestinal issues with oral methotrexate or require doses above a certain threshold, a healthcare provider may switch to an injectable form. Subcutaneous (under the skin) injection is the most common parenteral method and offers several benefits.

Benefits of subcutaneous methotrexate:

• Improved bioavailability: Subcutaneous injection allows for more predictable and higher absorption of the medication, especially at certain doses, compared to oral forms.
• Reduced side effects: Since the medication bypasses the digestive tract, it often leads to fewer gastrointestinal side effects, which can improve adherence and patient comfort.
• Faster response: Some studies suggest that subcutaneous administration may result in a faster and more robust clinical response compared to oral therapy.

Procedure for self-injection:

1. Prepare your supplies: Gather the prefilled syringe or auto-injector, alcohol pads, and a sharps container. Allow the medication to warm to room temperature for about 30 minutes.
2. Choose an injection site: Common sites include the abdomen or thigh. Alternate injection sites each week to prevent irritation. Avoid injecting into areas that are bruised, red, or have active psoriasis plaques.
3. Clean the area: Wash your hands thoroughly. Use an alcohol pad to clean the injection site and let it air dry.
4. Inject the medication: For a prefilled syringe, pinch a fold of skin and inject at a 90-degree angle. For an auto-injector, place the device firmly against the skin and press the injection button. The device will deliver the dose automatically.
5. Remove the needle: Once the injection is complete, withdraw the needle and apply gentle pressure with sterile gauze. Do not rub the site.
6. Dispose safely: Place the used syringe or auto-injector into the sharps container. Never recap the needle.

The crucial role of folic acid

Methotrexate is a folate antagonist, and long-term use can deplete the body's folic acid stores, leading to an increase in side effects. To counteract this, doctors prescribe a folic acid supplement to be taken weekly. Taking folic acid does not reduce methotrexate's efficacy for psoriasis but significantly improves tolerability and helps prevent adverse effects like mouth sores, nausea, and liver enzyme abnormalities. It is important to take the folic acid on a different day than the methotrexate dose to ensure the medication's effectiveness is not compromised.

Essential monitoring and safety precautions

Because methotrexate can affect the liver, kidneys, and bone marrow, regular monitoring is mandatory. Your doctor will order blood tests at scheduled intervals to check your blood cell counts, liver function, and kidney function.

Important safety considerations:

• Alcohol consumption: Avoid alcohol entirely while on methotrexate, as the combination can increase the risk of liver damage.
• Pregnancy and conception: Methotrexate is a known teratogen and is contraindicated in pregnancy for both men and women attempting conception. Use effective contraception during treatment. Men should wait at least three months, and women should wait at least one ovulatory cycle (or four months), after stopping methotrexate before attempting to conceive.
• Drug interactions: Inform your doctor about all medications you are taking, including over-the-counter drugs, as some can interfere with methotrexate. Non-steroidal anti-inflammatory drugs (NSAIDs), for example, can increase the risk of methotrexate toxicity.
• Infections and sun sensitivity: Report any signs of infection immediately, as methotrexate can affect your immune system. Your skin may also become more sensitive to sunlight, so protect yourself with sunscreen and clothing.

Oral vs. injectable methotrexate for psoriasis

Feature	Oral Methotrexate	Injectable Methotrexate
Administration	Convenient tablets or liquid.	Subcutaneous (under the skin) injections.
Bioavailability	Can be less reliable, especially at higher doses.	Higher and more predictable absorption into the bloodstream.
Gastrointestinal Side Effects	More common, including nausea and upset stomach.	Often fewer or less severe GI side effects.
Efficacy	May be limited by absorption at higher oral quantities.	Can be effective at various administered amounts, leading to a potentially greater response.
Patient Comfort	May be preferred by those with a fear of needles.	Requires comfort with needles, but can reduce systemic discomfort.
Adherence	Can be high due to ease of use. Split administration may be confusing.	Can be high due to better tolerability and patient training.

Conclusion

Properly administering methotrexate is key to managing moderate-to-severe psoriasis effectively. For most patients, oral methotrexate is the initial and most convenient approach. However, for those with gastrointestinal intolerance or a need for doses above a certain limit, injectable (subcutaneous) administration offers improved bioavailability and a more favorable side-effect profile. Whichever route is chosen, adherence to the once-weekly schedule, diligent use of folic acid supplementation, and regular monitoring by a healthcare provider are essential for safety and long-term success. Always consult your healthcare provider to determine the best approach and to stay vigilant for potential side effects. For more information, the National Psoriasis Foundation provides excellent patient resources and detailed treatment information (https://www.psoriasis.org/methotrexate/).

Frequently Asked Questions

How often do you take methotrexate for psoriasis?

Methotrexate for psoriasis is typically taken once a week. It is crucial to follow this weekly schedule exactly as prescribed by your doctor to avoid serious and potentially fatal side effects.

Should methotrexate for psoriasis be given orally or by injection?

The choice between oral and injectable methotrexate depends on individual needs. Oral is convenient but may cause more GI side effects. Injections (subcutaneous) may be preferred for amounts above a certain level or in patients experiencing nausea with oral tablets, as they offer better absorption and fewer GI issues.

Why is folic acid taken with methotrexate for psoriasis?

Folic acid is taken with methotrexate to reduce side effects such as mouth sores, nausea, and liver problems. Methotrexate depletes the body's folate, and supplementation helps counteract this effect without decreasing the medication's efficacy for psoriasis.

What happens if you drink alcohol while taking methotrexate?

Combining methotrexate with alcohol significantly increases the risk of liver damage. It is strongly advised to abstain from alcohol entirely while on this medication.

How do you self-inject methotrexate for psoriasis?

To self-inject, first prepare the medication and sharps container. Choose an injection site like the abdomen or thigh, clean it, and pinch a fold of skin. Insert the needle at a 90-degree angle, inject the prescribed amount, and then dispose of the used syringe or auto-injector in a sharps container.

What monitoring is required when taking methotrexate for psoriasis?

Regular monitoring with blood tests is necessary while on methotrexate. Your healthcare provider will check your blood cell counts, liver function, and kidney function at regular intervals to detect any potential toxicities early.

When should methotrexate be avoided for psoriasis?

Methotrexate is contraindicated in individuals with chronic liver disease, alcoholism, significant anemia, or impaired kidney function. It must also be stopped before a man or woman attempts to conceive, as it can cause birth defects.