Methotrexate for psoriasis: treatment regimen and dosages

Methotrexate for psoriasis is one of the components of the main treatment of the disease.

Psoriasis is characterized by limited or widespread damage to the skin, the development of inflammation, itching. The pathological process can involve both the skin and joints, and even internal organs.

Psoriasis is considered a chronic disease that occurs with periodic exacerbations and stages of relief (remission).

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Indications of methotrexate for psoriasis

Methotrexate is used to treat severe forms of psoriasis. The purpose of prescribing the drug is:

• acceleration of tissue regeneration;
• stopping the development of the inflammatory reaction;
• relief of movement in psoriasis of the joints.

Despite the fact that Methotrexate is a drug from the cytostatic group, its action is not limited to the properties of an antitumor drug. Methotrexate slows down the active progression of psoriasis, relieves pain. The earlier the treatment is started, the more effective the effect of the drug will be.

In addition to severe forms of psoriasis, Methotrexate is used to treat rheumatoid arthritis, severe mycotic lesions, trophoblastic neoplasms, and acute lymphoblastic leukemia.

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Release form

Methotrexate is an antitumor drug that is produced in the form of tablets for oral use, or as a solution for injection (intramuscular or intravenous injections).

The active ingredient of the drug is methotrexate, an antineoplastic agent, an antimetabolite, a structural analogue of folic acid.

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Pharmacodynamics

Methotrexate is a drug that belongs to the group of antimetabolites and exhibits cytostatic and immunosuppressive effects. The structure of this substance is close to the structural structure of folic acid, but Methotrexate is considered its antagonist. Other properties of Methotrexate:

• inhibition of the conversion of dihydrofolic acid to tetrahydrofolic acid;
• suppression of DNA production and the process of cell division, RNA and protein production.

The most sensitive to the action of the drug are tumor tissues, bone marrow, epithelium and cellular structures of the fetus.

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Pharmacokinetics

After the substance Methotrexate enters the body, the maximum amount of the drug is detected after about 45 minutes. The active component freely spreads in the tissues and fluids of the body. In the kidneys, the remains of the drug are detected for several weeks, in the liver - for several months.

When a standard amount of the drug Methotrexate is administered, its penetration through the blood-brain barrier is not observed.

Metabolic processes occur mainly in the liver, with the formation of the active substance – polyglutamate.

The half-life depends on the dose of Methotrexate taken, and can range from 3 to 10 hours when taking a small amount of the drug, or from 8 to 15 hours when taking a significant amount of the drug.

Most of the drug (at least 90%) is excreted from the body through the kidneys, and only a small amount is removed with bile, throughout the day.

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Dosing and administration

Methotrexate for psoriasis is taken in the amount of 10-25 mg per week, with a gradual increase in dosage. The initial dose is usually 5 to 10 mg once a week.

The drug can be taken orally, or as intramuscular or intravenous injections, depending on the patient's condition.

The maximum amount of the drug is 30 mg per week.

Methotrexate regimen for psoriasis

The regimen for taking Methotrexate for psoriasis should comply with the following rules:

• the next dose should be taken on the same day of the week, at the same time;
• the drug is prescribed with a gradual increase in dosage;
• At the moment when the clinical effect of Methotrexate becomes noticeable, they proceed to a gradual reduction in dosage, stopping at the optimally low amount of the drug.

Currently, the most commonly used regimens for taking Methotrexate are:

1. The course of treatment is 4-6 weeks, three times a week in the amount of 2.5 mg.
2. With increase and regression of acute symptoms, 10 to 30 mg once a week. The course of treatment is 4-6 weeks.

For psoriasis, it is better to take methotrexate before meals or 1-1.5 hours after meals.

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Use of methotrexate for psoriasis during pregnancy

Methotrexate has been shown to have significant teratogenic effects and can cause fetal death or intrauterine defects.

In situations where a patient becomes pregnant while taking Methotrexate, the issue of induced abortion should be raised, as the risk of damage to the fetus is considered very likely. Women of childbearing age are usually advised to take oral contraceptives before starting treatment with the drug to avoid possible pregnancy.

During lactation, taking Methotrexate is also contraindicated, since the drug tends to enter breast milk.

Contraindications

Methotrexate is not prescribed for psoriasis:

• during pregnancy and breastfeeding;
• in case of serious liver and/or kidney pathologies;
• in case of serious disorders of hematopoiesis or in case of a significant drop in hemoglobin;
• in case of exacerbation of infectious pathologies;
• in case of HIV infection;
• if you are prone to allergy to methotrexate;
• in childhood (up to 3 years).

Methotrexate for psoriasis is used only under constant supervision of a doctor in the following situations:

• when fluid accumulates in the abdominal or pleural cavity;
• for gastric ulcer and duodenal ulcer;
• in case of ulcerative lesion of the intestine;
• in case of severe dehydration;
• for gout;
• after radiation or chemotherapy treatment;
• during viral, microbial or fungal infections.

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Side effects of methotrexate for psoriasis

Taking Methotrexate for psoriasis can be accompanied by a considerable number of side effects. The most common symptoms are:

• anemia, changes in blood picture;
• weight loss, bouts of nausea and vomiting, inflammatory changes in the mucous membranes, erosions and ulcers in the digestive system;
• inflammation of liver tissue, pancreatitis;
• headaches, sleep disturbances, numbness in the extremities, convulsions;
• instability of emotional state;
• conjunctivitis, temporary visual impairment;
• decreased blood pressure, thrombosis, pericarditis;
• pulmonary fibrosis, pulmonary obstruction, interstitial pneumonia;
• kidney dysfunction, inflammation of the bladder, deterioration of sperm quality, deterioration of libido, difficulty conceiving, miscarriage;
• redness of the skin, acne, burning;
• joint pain, muscle pain, osteoporosis;
• allergy, sepsis, hyperhidrosis;
• development of lymphoma.

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Overdose

Excess of the substance Methotrexate in the blood is characterized by the following symptoms:

• sudden and increasing weight loss;
• dizziness, blurred vision;
• depressive state;
• coma;
• increasing leukopenia.

To eliminate signs of overdose, calcium folinate is prescribed, which is a substance that neutralizes the toxic effects of Methotrexate.

Calcium folinate is administered as an intravenous infusion, in the amount of 75 mg over 12 hours. After that, they switch to intramuscular administration of the substance, in the amount of 12 mg four times with a time interval of six hours.

In the event of negative side effects from treatment with Methotrexate, intramuscular administration of calcium folinate in an amount of 6 to 12 mg four times with a six-hour time interval is used.

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Interactions with other drugs

When using Methotrexate for psoriasis, there may be a weakening of the natural immune response.

The combination of Methotrexate and the administration of live vaccines can lead to pronounced antigenic reactions.

Acceleration of the elimination of Methotrexate can be caused by drugs such as salicylates, sulfonamides, tetracycline antibiotics, chloramphenicol, cyclophosphamide, and sleeping pills.

Methotrexate is eliminated primarily through the kidneys, so interactions with medications that are eliminated in the same way may occur. These interactions may result in changes in the blood levels of Methotrexate.

In combination with the drug Probenecid, the dosage of Methotrexate is reduced.

Methotrexate is incompatible with hepatotoxic and nephrotoxic drugs, as well as with alcohol.

Combinations of the drug Methotrexate and nonsteroidal anti-inflammatory drugs may lead to increased toxic side effects.

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Storage conditions

Methotrexate is stored at a moderate room temperature not exceeding +25°C, out of the reach of children.

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Shelf life

The shelf life of the medicine is up to 2 years.

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Reviews of taking Methotrexate for psoriasis

Methotrexate is a fairly potent drug, the use of which has its positive and negative sides.

On the one hand, Methotrexate really helps with psoriasis. This drug is often prescribed in the most advanced and complicated cases of the disease, when it is not possible to achieve relief with other medications.

On the other hand, Methotrexate has a long list of side effects. And they are far from harmless: it can be a lesion of the respiratory, cardiovascular, nervous system, as well as some other organs.

Whether to take Methotrexate for psoriasis or not is a decision that the patient must make after consulting with the attending physician. If there are no contraindications, then you can take a trial course of treatment with the drug, adhering to the optimally effective, but minimal dosage. If undesirable symptoms appear, you must inform the doctor about them - perhaps he will change the dosage or replace the drug with another, more suitable for your body.

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