Indications
Metorax Tablet is used for:
Burkitt's lymphoma, Choriocarcinoma, Mycosis fungoides, Crohn's disease, Psoriasis, Osteosarcoma, Breast cancer, lymphosarcoma, Acute lymphoblastic leukaemia, Rheumatoid arthritis
Adult Dose
Adult:
PO
Burkitt's lymphoma 10-25 mg/day for 4-8 days, repeat after 7-10 days.
Choriocarcinoma 15-30 mg/day for 5 days, repeat after an interval of at least 1 wk for 3-5 courses.
Mycosis fungoides 2.5-10 mg/day to induce remission.
Rheumatoid arthritis 7.5 mg once wkly, adjust if needed. Up to 20 mg/wk. Crohn's disease 12.5-22.5 mg once wkly for up to 1 yr.
PO/IV/IM Psoriasis 10-25 mg once wkly, adjust subsequent doses if needed.
IV
Osteosarcoma 12-15 g/m2 as infusion, followed by folinic acid.
Breast cancer 10-60 mg/m2 often w/ cyclophosphamide and fluorouracil.
Advanced lymphosarcoma Up to 30 mg/kg, followed by folinic acid rescue.
Acute lymphoblastic leukaemia Maintenance: 2.5 mg/kg every 14 days.
PO/IM
Acute lymphoblastic leukaemia Maintenance: 15 mg/m2 1-2 times/wk w/ other agents.
IM Choriocarcinoma 15-30 mg/day for 5 days. Repeat after at least 1 wk for 3-5 courses.
Mycosis fungoides 50 mg/wk in 1-2 divided doses.
Crohn's disease 25 mg once wkly for 16 wk. Maintenance: 15 mg/wk.
Intrathecal Meningeal leukaemia 12 mg/m2 (Max: 15 mg) once wkly for 2-3 wk, then once mthly.
Hepatic impairment
Bilirubin 3.1-5.0 mg/dL or AST > 3 times ULN: Give 75% of dose
Bilirubin >5.0 mg/dL: Avoid use
Child Dose
Polyarticular Juvenile Idiopathic Arthritis
Initial: 10 mg/m² PO/IM/SC qWeek
Meningeal Leukemia
<1 year: 6 mg intrathecally (IT) every 2-5 days
1-2 years: 8 mg IT every 2-5 days
2-3 years: 10 mg IT every 2-5 days
>3 years: 12 mg IT every 2-5 days
Renal Dose
Renal impairment:
CrCl (ml/min) Dosage Recommendation
61-80 75% of dose
51-60 70% of dose
10-50 30-50% of dose
<10 Avoid use
Intermittent hemodialysis: 50% of dose at normal dosing interval
Continuous renal replacement therapy: 50% of dose at normal dosing interval
Administration
Should be taken on an empty stomach. Best taken on an empty stomach. May be taken w/ meals to reduce GI discomfort. Avoid taking w/ milk-rich products.
IV/IM Preparation
Reconstitute with D5W or NS: 20-mg vial, up to 25 mg/mL; 1-g vial, up to 50 mg/mL
May dilute further for IV infusion
IV/IM Administration
Administer by IM, IV push, or IV infusion
Regular IV given with no more than 25 mg/mL
IV push: Administered at 10 mg/min
IV infusion (usually >100 mg): Administered over 30 minutes to 4 hours, or according to institutional protocol
High-dose therapy (uses 1-g vial): Administered over 4 hours
Specific dosing schemes vary, but high doses should be followed by leucovorin 24 hours after initiation of therapy to prevent toxicity
Contra Indications
Severe renal or hepatic impairment, pre-existing profound bone marrow suppression in patients with psoriasis or rheumatoid arthritis, alcoholic liver disease, AIDS, pre-existing blood dyscrasias, pregnancy (in patients with psoriasis or rheumatoid arthritis), breast-feeding.
Precautions
Hepatic or renal impairment, bone marrow depression, elderly, neonates. Ulcerative disorders of the GI tract. Monitor haematological, renal and hepatic function, and GI toxicity regularly.
Lactation: Drug excreted in breast milk; do not nurse
Pregnancy-Lactation
Pregnancy
Based on published reports and mechanism of action, can cause embryo-fetal toxicity and fetal death when administered to pregnant women
Verify pregnancy status of females of reproductive potential before initiating
Contraindicated in pregnant women with nonmalignant disease
Contraception
Females
Can cause fetal harm when administered to pregnant women;
Use effective contraception during and for 6 months after final dose
Males
Can cause chromosomal damage to sperm cells
Advise males with female partners of reproductive potential to use effective contraception during and for at least 3 months after final dose
Infertility
Females: Can cause impairment of fertility and menstrual dysfunction during and after cessation of therapy; unknown if infertility may be reversed in all affected females
Males: Can cause oligospermia or infertility during and after cessation of therapy; unknown if infertility may be reversed in all affected males
Lactation
Limited published literature report the presence of methotrexate in human milk in low amounts; no information is available on the effects on breastfed infants or milk production
Because of the potential for serious adverse reactions, including myelosuppression, from methotrexate in breastfed infants, advise women not to breastfeed during therapy and for 1 week after final dose
Interactions
Decreased effectiveness with folic acid and its derivatives.
Potentially Fatal: Increased toxicity with NSAIDs and salicylates; probenecid; some penicillins; aminoglycosides neomycin and paromomycin; sulfonamides such as sulfafurazole and sulfamethoxazole; co-trimoxazole or trimethoprim; nephrotoxic agents (e.g. cisplatin); ciclosporin; etretinate. Synergistic enhancement of effects with fluorouracil. Increased bioavailability of mercaptopurine. Reduces serum-valproate concentrations. Reduced serum concentrations with colestyramine. Increased serum concentrations with omeprazole.
Side Effects
Side effects of Methotrexate :
>10%
Arachnoiditis with intrathecal administration, Subacute toxicity with intrathecal administration (paralysis of extremities, cranial nerve palsy, seizure or coma), Demyelinating encephalopathy with cranial irradiation or other systemic chemotherapy, Reddening of skin, Hyperuricemia, Ulcerative stomatitis, Glossitis, Gingivitis, Nausea and vomiting, Diarrhea, Anorexia, Intestinal perforation, Mucositis (dose-dependent), Leukopenia, Thrombocytopenia, Renal failure, Azotemia, Nephropathy, Pharyngitis
1-10%
Alopecia, Photosensitivity, Rash, Abdominal distress, Malaise, Fatigue, Chills, fever, Decreased resistance to infection, Gastrointestinal hemorrhage, Myelosuppression, Disorders of lung, interstitial pneumonia (acute, chronic), Atrophy of liver, cirrhosis, hepatic fibrosis or necrosis, elevated liver function tests, hepatic failure
Potentially Fatal: Pulmonary reactions (e.g. interstitial lung disease); neurotoxicity (e.g. leukoencephalopathy, paresis, demyelination) with intrathecal use; foetal deaths.
Mode of Action
Methotrexate is a folic acid antagonist that inhibits DNA synthesis. It irreversibly binds to dihydrofolate reductase, inhibiting the formation of reduced folates, and thymidylate synthetase, resulting in inhibition of purine and thymidylic acid synthesis.
Note
Metorax 2.5mg Tablet generic name is Methotrexate. Metorax 2.5mg Tablet is manufactured by Renata LimitedMetorax is availble in all over Bangladesh.
Mes BD drug index information on Metorax Tablet is not intended for diagnosis, medical advice or treatment; neither intended to be a substitute for the exercise of professional judgment.