Metorax 10 mg Tablet

Metorax Tablet — Methotrexate

Indications

Neoplastic Diseases:

Treatment of gestational choriocarcinoma, chorioadenoma destruens and hydatidiform mole
In acute lymphoblastic leukemia
Used in combination with other chemotherapeutic agents in the treatment of advanced stage non-Hodgkin’s lymphomas ... Read moreNeoplastic Diseases:

Treatment of gestational choriocarcinoma, chorioadenoma destruens and hydatidiform mole
In acute lymphoblastic leukemia
Used in combination with other chemotherapeutic agents in the treatment of advanced stage non-Hodgkin’s lymphomas
Treatment of breast cancer, epidermoid cancers of the head and neck, advanced mycosis fungoides (cutaneous T-cell lymphoma) and lung cancer, particularly squamous cell and small cell types.

Rheumatoid Arthritis including Polyarticular-Course Juvenile Rheumatoid Arthritis: Indicated in the management of selected adults with severe, active rheumatoid arthritis, or children with active polyarticular-course juvenile rheumatoid arthritis, who have had an insufficient therapeutic response to, or are intolerant of, an adequate trial of first-line therapy including full dose non-steroidal anti-inflammatory agents (NSAIDs)Psoriasis: Indicated in the symptomatic control of severe, recalcitrant, disabling psoriasis that is not adequately responsive to other forms of therapy.

Mechanism of Action

Methotrexate inhibits dihydrofolic acid reductase. Dihydrofolates must be reduced to tetrahydrofolates by thisenzyme before they can be utilized as carriers of one-carbon groups in the synthesis of purine nucleotides and thymidylate. Therefore, methotrexate interferes with DNA synthesis, repair, and cellular replication. Actively proliferating tissues such as malignant cells, bone marrow, fetal cells, buccal and intestinal mucosa, and cells of the urinary bladder are in general more sensitive to this effect of methotrexate. When cellular proliferation in malignant tissues is greater than in most normal tissues, methotrexate may impair malignant growth without irreversible damage to normal tissues. In psoriasis, the rate of production of epithelial cells in the skin is greatly increased over normal skin. This difference in proliferation rates is the basis for the use of methotrexate to control the psoriatic process.

Contraindications

Alcoholism, alcoholic liver disease or other chronic liver disease
Immunodeficiency syndromes
Pre-existing blood dyscrasias, such as bone marrow hypoplasia, leukopenia, thrombocytopenia, or significant anemia
Hypersensitivity to methotrexate
Pregnant women with psoriasis or rheumatoid arthritis
Women of childbearing potential
Nursing mothers
Pregnancy should be avoided if either partner is receiving methotrexate; during and for a minimum of three months after therapy for male patients, and during and for at least one ovulatory cycle after therapy for female patients

Side Effects

The most frequently reported adverse reactions include ulcerative stomatitis, leukopenia, nausea and abdominal distress
Other frequently reported adverse effects are malaise, undue fatigue, chills and fever, dizziness and decreased resistance to infection
Metorax has been reported to cause impairment of fertility, oligospermia and menstrual dysfunction in humans, during and for a short period after cessation of therapy

Drug Interactions

NSAIDs: Should not be administered prior to or concomitantly with high doses of Metorax, such as used in the treatment of osteosarcoma
Salicylates, Phenylbutazone, Phenytoin and Sulfonamides: Toxicity may be increased Penicillin, Theophylline, Probenecid, Azathioprine, Retinoids,
Sulfasalazine: Should be closely monitored for possible increased risk of hepatotoxicity
Cisplatin: Caution must be exercised if high-dose Metorax is administered in combination
Mercaptopurine: Metorax increases the plasma levels of mercaptopurine
Tetracycline, Chloramphenicol and Nonabsorbable Broad Spectrum Antibiotics: May decrease intestinal absorption of Metorax
Vitamin preparations containing folic acid or its derivatives: Decreases responses to systemically administered Metorax
Trimethoprim/Sulfamethoxazole: Rarely increases bone marrow suppression

Pregnancy and Lactation

US FDA Pregnancy Category X. Methotrexate should be used in the treatment of neoplastic diseases only when the potential benefit outweighs the risk to the fetus. It is contraindicated in nursing mothers.

Precautions and Warnings

Metorax formulations and diluents containing preservatives must not be used for intrathecal or high dose Metorax therapy
It is necessary to follow patients on Metorax closely for toxic effects
If adverse reactions occur, the drug should be reduced in dosage or discontinued and appropriate corrective measures should be taken. If necessary, this could include the use of leucovorin calcium
If Metorax therapy is reinstituted, it should be carried out with caution, with adequate consideration of further need for the drug and increased alertness as to possible recurrence of toxicity
Persistent liver function test abnormalities, &/or depression of serum albumin may be indicators of serious liver toxicity & require evaluation
Folate deficiency: May increase Metorax toxicity

Use in Special Populations

Pediatric patients: Benefits should be weighed against the potential risk before using Metorax alone or in combination with other drugs, especially in pediatric patients or young adults.Geriatric patients: Elderly patients should be closely monitored for early signs of hepatic, bone marrow and renal toxicity.

Overdose

Leucovorin is indicated to diminish the toxicity and counteract the effect of inadvertently administered overdosages of Metorax and its administration should begin as promptly as possible.

Storage

Store at a temperature not exceeding 30°C in a dry place. Protect from light & moisture.

Medical Disclaimer: This information is provided for educational purposes only and is not intended as medical advice. Always consult a qualified healthcare professional before starting, changing, or stopping any medication.