Methotrexate Injection 50 mg/mL

Adult dosage

(1) Severe active rheumatoid arthritis The recommended initial dose is 7.5mg of methotrexate by subcutaneous injection once weekly. Depending on the patient's tolerability and disease progression, the dose may be gradually increased by 2.5mg per week. Do not exceed a total dose of 25mg per week. (2) Severe, refractory psoriasis unresponsive to other medicines One week before treatment, a test dose of 5～10 mg of methotrexate should be administered once parenterally to test for idiosyncratic adverse reactions. The usual dose is 10～25 ㎎ once weekly, administered orally or by subcutaneous injection. (3) Reduce the dose in patients with impaired renal function. (4) Administer with extreme caution to patients with hepatic impairment. Do not administer if the bilirubin level is 5mg/L or higher. (5) Consider dose reduction carefully in elderly patients. (6) Consider reducing the dose when switching from oral administration to injection.

This drug should only be taken once a week when treating rheumatoid arthritis or psoriasis. Medication errors can lead to serious side effects, so the dosage instructions and precautions must be strictly followed. Caution is advised as the blood concentration may increase and toxicity may occur when taken with proton pump inhibitors. Patients with poor liver or kidney function, blood disorders, severe infections, pregnant women, and breastfeeding mothers should not use this medication. If gastrointestinal symptoms such as diarrhea or stomatitis occur, consult a doctor immediately, and patients with gastric ulcers should also be cautious. Hematological suppression and gastrointestinal disturbances may frequently occur during treatment, so regular blood tests and liver and kidney function tests are necessary. This drug has strong toxicity and should be administered under the supervision of a professional, and if signs of side effects appear during treatment, immediate adjustments should be made. This medication may pose serious risks to the fetus during pregnancy, so women who are pregnant or may become pregnant should not use it. Breastfeeding women should stop breastfeeding as this drug can be excreted in breast milk and may affect the baby. Care should be taken when driving or operating machinery, as fatigue or dizziness may occur. There are many drug interactions, so patients should inform healthcare providers of any medications they are taking and be closely monitored. In case of overdose, rapid treatment, including the administration of specific antidotes, is necessary. Store in a cool, dark place out of reach of children, and do not use expired medication.

Hematologic suppression, gastrointestinal disorders, stomatitis, dyspepsia, nausea, loss of appetite, gastric ulcer, diarrhea, pharyngitis, enteritis, vomiting, gastrointestinal ulcer, malabsorption, hematemesis, massive bleeding, toxic megacolon, vesicles, erythema, itching, photosensitivity, hair loss, rheumatic nodular hyperplasia, herpes zoster, vasculitis, herpes skin rash, urticaria, increased pigmentation, acne, petechiae, skin-mucous membrane syndrome, toxic epidermal necrolysis, increased nail pigmentation changes, acute paronychia, furunculosis, telangiectasia, skin peeling, exfoliative dermatitis, local skin reactions at the subcutaneous injection site, allergic reactions, anaphylactic shock, allergic vasculitis, fever, conjunctivitis, infection, sepsis, impaired wound healing, pleural effusion, pericardial effusion, acute cardiac tamponade, hypogammaglobulinemia, edema, diabetes induction, headache, fatigue, drowsiness, dizziness, confusion, depression, cognitive dysfunction, visual disturbances, pain, myasthenia, sensory abnormalities, taste changes, convulsions, meningitis, paralysis, encephalopathy, white matter encephalopathy, visual impairment, retinopathy, elevated aminotransferases, cirrhosis, liver atrophy, liver fibrosis, fatty degeneration, decreased serum albumin, acute hepatitis, liver failure, myocarditis, pericardial effusion, cardiac tamponade, hypotension, thromboembolism, pneumonia, interstitial alveolitis associated with eosinophilia, pulmonary fibrosis, pneumocystis pneumonia, dyspnea, bronchial asthma, pleural effusion, alveolar hemorrhage, leukopenia, anemia, thrombocytopenia, pancytopenia, agranulocytosis, severe bone marrow suppression, lymphoproliferative disorders, inflammation and ulcers of the bladder and vagina, renal impairment, urination disorders, renal failure, oliguria, anuria, electrolyte disturbances, vaginitis, vaginal ulcers, diminished libido, erectile dysfunction, gynecomastia, oligospermia, oocyte maturation deficiency, spermatogenesis deficiency, infertility, menstrual disorders, vaginal discharge, arthralgia, myalgia, osteoporosis, osteonecrosis of the jaw, lymphoma

Store this medication in a sealed container to avoid exposure to air and light, and it is recommended to keep it at a cool temperature below 25 degrees Celsius. By storing it this way, the efficacy of the medication can be maintained, and deterioration can be prevented.

Appearance

A transparent yellowish-brown solution in a colorless transparent glass prefilled syringe fitted into a pen injector.

Package unit

1 prefilled syringe pen/box [1 vial (10 mg/0.2 mL)], 1 prefilled syringe pen/box [1 vial (15 mg/0.3 mL)], 1 prefilled syringe pen/box [1 vial (20 mg/0.4 mL)], 1 prefilled syringe pen/box [1 vial (25 mg/0.5 mL)]