Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
MEXATE-AQ vs CLADRIBINE
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Methotrexate is a folate analog that inhibits dihydrofolate reductase (DHFR), blocking the conversion of dihydrofolate to tetrahydrofolate, which is required for the synthesis of purines and pyrimidines. This leads to inhibition of DNA, RNA, and protein synthesis, particularly in rapidly dividing cells. It also has immunosuppressive effects via inhibition of T cell activation and reduction of inflammatory cytokines.
Cladribine is a purine nucleoside analog that is phosphorylated intracellularly to its active triphosphate form, which inhibits DNA synthesis and repair, leading to cell death, particularly in lymphocytes. It also depletes adenosine deaminase (ADA) and accumulates in cells with high deoxycytidine kinase activity.
FDA-approved: Chemotherapy for gestational choriocarcinoma, chorioadenoma destruens, hydatidiform mole, acute lymphocytic leukemia, meningeal leukemia, breast cancer, head and neck cancer, cutaneous T-cell lymphoma, lung cancer, non-Hodgkin's lymphoma, osteosarcoma, and mycosis fungoides.,FDA-approved: Severe, active rheumatoid arthritis (RA) in adults who have failed first-line therapy.,FDA-approved: Pediatric patients with polyarticular juvenile idiopathic arthritis (p JIA) who have failed first-line therapy.,FDA-approved: Psoriasis (severe, recalcitrant) in adults.,Off-label: Prevention of graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation.,Off-label: Crohn's disease (maintenance of remission in steroid-dependent patients).,Off-label: Ectopic pregnancy (medical management).
FDA-approved: Treatment of hairy cell leukemia.,Off-label: Chronic lymphocytic leukemia (CLL), multiple sclerosis (relapsing forms), Waldenström macroglobulinemia, cutaneous T-cell lymphoma, and as part of conditioning regimens for hematopoietic stem cell transplantation.
Methotrexate: 7.5-25 mg orally once weekly for rheumatoid arthritis; 30-40 mg/m2 IV weekly for mycosis fungoides; 50-75 mg/m2 IV over 4-6 hours weekly for osteosarcoma; 15-20 mg/m2 IM weekly for psoriasis.
0.09 mg/kg/day IV over 2 hours for 7 consecutive days; or 0.14 mg/kg/day IV over 2 hours for 5 consecutive days (total dose 0.7 mg/kg per course).
Terminal elimination half-life is approximately 3–10 hours for low doses (<30 mg/m²) and 8–15 hours for high doses (>80 mg/m²). Prolonged to 48–72 hours in patients with third-space effusions or renal impairment.
Terminal elimination half-life is approximately 5.4 hours (range 4.6–6.7 hours) after intravenous administration; prolonged in renal impairment.
Metabolized primarily in the liver to polyglutamates (which are active metabolites) via folylpolyglutamate synthetase. Partial metabolism via aldehyde oxidase and xanthine oxidase to 7-hydroxymethotrexate. Methotrexate is also partially metabolized by intestinal flora. Elimination is primarily renal via glomerular filtration and active tubular secretion.
Cladribine is primarily metabolized intracellularly by deoxycytidine kinase to its active triphosphate. It is also phosphorylated by deoxyguanosine kinase in mitochondria. Catabolism involves deamination by adenosine deaminase (ADA) to 2-chloroadenine, which is further metabolized.
Renal excretion predominates (80-90% as unchanged drug) via glomerular filtration and active tubular secretion. Biliary/fecal elimination is minor (<10%).
Renal (approximately 50% as unchanged drug); fecal elimination is minimal (<5%).
Approximately 50–60% bound primarily to albumin. Weakly bound and readily displaceable by other drugs.
Approximately 20–30% bound to plasma proteins.
Vd: 0.4–0.8 L/kg (initial 0.18 L/kg, steady-state 0.4–0.8 L/kg). Distributes into third-space fluids (pleural, ascitic), leading to prolonged elimination.
Approximately 4.5 L/kg (range 2.3–9.6 L/kg), indicating extensive tissue distribution.
Oral: 30–60% (dose-dependent; saturable absorption at high doses). Intramuscular: 80–100%. Subcutaneous: approximately 90%.
Oral: approximately 37–55% (first-pass metabolism); subcutaneous: approximately 100%.
For GFR 40-59 m L/min: reduce dose by 20%; GFR 20-39 m L/min: reduce dose by 40%; GFR <20 m L/min: contraindicated.
GFR <50 m L/min: reduce dose by 50%; GFR <10 m L/min: avoid use.
Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50%; Child-Pugh C: contraindicated.
Child-Pugh Class B: reduce dose by 50%; Child-Pugh Class C: contraindicated.
For acute lymphoblastic leukemia (ALL): 15-20 mg/m2 IM once weekly as maintenance; for osteosarcoma: 12 g/m2 IV over 4 hours with leucovorin rescue.
0.09 mg/kg/day IV over 2 hours for 7 consecutive days; or 0.14 mg/kg/day IV over 2 hours for 5 consecutive days (total dose 0.7 mg/kg per course). No specific pediatric dose adjustments beyond weight-based dosing.
Start at lowest recommended dose (e.g., 5 mg orally once weekly) with careful monitoring for renal function, hepatic function, and folate levels; adjust based on tolerance.
No specific dose adjustment recommended; monitor renal function and adjust accordingly.
Boxed Warning: Methotrexate can cause fetal death or teratogenic effects when administered to pregnant women. It is contraindicated in pregnant women with psoriasis or RA. It also has a boxed warning for severe toxicity and death due to inadvertent daily (as opposed to weekly) dosing; hepatic toxicity, including acute hepatitis and chronic hepatic fibrosis; myelosuppression, including severe bone marrow suppression; and pulmonary toxicity, including acute or chronic interstitial pneumonitis. Additionally, anaphylactic reactions can occur. For patients with psoriasis, methotrexate should be used only for severe, recalcitrant cases unresponsive to other therapy.
WARNING: Neurotoxicity and Hematologic Toxicity. Cladribine can cause severe bone marrow suppression (neutropenia, anemia, thrombocytopenia) and neurotoxicity (including paralysis, coma, and death). Dose-dependent and more frequent in high doses.
Fatal toxicities (including hematologic, hepatic, pulmonary, renal, dermatologic, and GI) can occur with methotrexate; monitor closely.,Hepatic toxicity: Monitor liver function tests; avoid or use with caution in patients with active liver disease or alcohol abuse.,Pulmonary toxicity: Acute or chronic interstitial pneumonitis may occur; monitor for cough, fever, dyspnea, and hypoxia.,Myelosuppression: Monitor CBC and platelet counts regularly; severe pancytopenia can occur.,Renal toxicity: Adequate renal function is essential; avoid NSAIDs, salicylates, and other nephrotoxic drugs if possible.,Gastrointestinal toxicity: Mucositis, ulcerative stomatitis, diarrhea, and hemorrhagic enteritis may occur.,Dermatologic toxicity: Phototoxicity, radiation recall, and severe skin reactions (including Stevens-Johnson syndrome) can occur.,Immunosuppression: Increased risk of infections, including opportunistic infections; avoid live vaccines.,Carcinogenicity: Increased risk of lymphoproliferative disorders (may be reversible with discontinuation).,Concomitant use with proton pump inhibitors (PPIs) may increase methotrexate levels.
Myelosuppression: Monitor blood counts regularly; dose adjustment or discontinuation may be needed.,Neurotoxicity: Risk increased with high doses and in patients with renal impairment.,Nephrotoxicity: Use with caution in renal impairment; reduce dose if Cr Cl < 60 m L/min.,Hepatotoxicity: Monitor liver function tests.,Secondary malignancies: Increased risk of myelodysplasia and acute myeloid leukemia.,Infections: Increased susceptibility due to lymphopenia; consider prophylaxis.
Hypersensitivity to methotrexate or any component of the formulation.,Pregnancy and breastfeeding (due to risk of fetal death/teratogenicity and excretion in breast milk).,Patients with psoriasis or RA who have alcoholism, alcoholic liver disease, chronic liver disease, or overt immunodeficiency.,Pre-existing blood dyscrasias (severe anemia, leukopenia, neutropenia, thrombocytopenia).,Concomitant use with live vaccines.
Hypersensitivity to cladribine or any component of the formulation.,Pre-existing severe bone marrow suppression (e.g., neutropenia, thrombocytopenia) unless due to underlying disease.,Pregnancy: Can cause fetal harm.,Lactation: Discontinue nursing or drug.
Avoid folic acid-rich foods (leafy greens, fortified grains) in large amounts during methotrexate therapy as they may reduce efficacy. No specific food-drug interactions; maintain a well-balanced diet.
No significant food interactions. Avoid grapefruit juice due to potential CYP3A4 interaction (though minimal). Maintain adequate hydration to prevent tumor lysis syndrome in hematologic malignancies.
FDA Pregnancy Category X. First trimester: High risk of miscarriage, CNS defects, craniofacial anomalies. Second trimester: IUGR, skeletal abnormalities. Third trimester: Neonatal bone marrow suppression, immunosuppression.
FDA Pregnancy Category D. First trimester: Avoid due to known teratogenicity in animal studies (skeletal and visceral malformations) and potential for MDS and AML. Second and third trimesters: Risk of fetal myelosuppression, intrauterine growth restriction, and preterm labor. Cladribine crosses the placenta and may cause fetal hematopoietic suppression.
Contraindicated. Methotrexate is excreted in breast milk; accumulation may occur in nursing infants due to immature renal function. M/P ratio not established; theoretical risk of serious adverse effects.
Contraindicated during breastfeeding. Cladribine is excreted into human milk; M/P ratio not determined. Potential for severe adverse effects in nursing infants, including myelosuppression and immunosuppression. Discontinue breastfeeding during therapy and for at least 7 days after last dose.
Contraindicated in pregnancy; no dose adjustment recommended due to teratogenicity. In lactating females, discontinue breastfeeding or avoid use.
No established dose adjustments in pregnancy. Use is contraindicated. If unavoidable, lowest effective dose and close monitoring for maternal and fetal toxicity. Pharmacokinetic changes in pregnancy (increased volume of distribution, renal clearance) may reduce exposure; however, risks outweigh benefits.
Mexate-AQ (methotrexate) requires folic acid supplementation to reduce gastrointestinal and hematologic toxicity. Administer leucovorin rescue after high-dose therapy. Avoid NSAIDs, salicylates, and sulfonamides due to increased methotrexate toxicity. Monitor renal function, liver enzymes, and blood counts regularly. Contraindicated in pregnancy, breastfeeding, and active infections.
Cladribine is a purine nucleoside analog that causes lymphocyte depletion, effective in hairy cell leukemia and multiple sclerosis. Monitor for severe lymphopenia, opportunistic infections (e.g., herpes zoster, tuberculosis), and delayed myelosuppression. Do not administer live vaccines during or after treatment. Due to high bioavailability after subcutaneous administration, adjust dose for renal impairment. Hypersensitivity reactions may occur; premedicate with antihistamines if needed.
Take exactly as prescribed; do not change dose without consulting your doctor.,Avoid alcohol completely while on this medication.,Report any signs of infection (fever, sore throat), unusual bleeding, or mouth ulcers immediately.,Use effective contraception during treatment and for at least 3 months after stopping.,Do not take any over-the-counter medications, especially NSAIDs (ibuprofen, naproxen), without permission.,Drink plenty of fluids to prevent kidney damage.,Attend all scheduled blood tests and appointments.,Capsules should be swallowed whole; do not crush or chew.
Cladribine can significantly lower your white blood cell count, increasing infection risk. Report fever, chills, or sore throat immediately.,Avoid live vaccines (e.g., MMR, shingles) during and for at least 6 months after treatment.,You may experience fatigue, nausea, headache, or skin reactions at injection site. These are common but report severe symptoms.,Use effective contraception during treatment and for at least 6 months after the last dose. Cladribine may harm a fetus.,You will need regular blood tests to monitor your blood cell counts, liver, and kidney function.
No interactions on record
"The combination of cabazitaxel and cladribine may potentiate myelosuppression due to overlapping bone marrow toxicity profiles. Cabazitaxel, a taxane antineoplastic, inhibits microtubule disassembly, while cladribine, a purine analog, incorporates into DNA and induces apoptosis in dividing and resting lymphocytes. Concurrent use increases the risk of severe neutropenia, thrombocytopenia, and anemia, potentially leading to febrile neutropenia or bleeding complications."
"Cladribine, a purine nucleoside analog with potent immunosuppressive properties, may reduce the pharmacodynamic effects of cardiac glycosides such as acetyldigitoxin. This interaction is hypothesized to occur through cladribine-induced modulation of myocardial cellular signaling pathways that decrease sensitivity to digitalis compounds, potentially leading to reduced inotropic efficacy. Clinically, this could manifest as diminished control of heart rate in patients with atrial fibrillation or worsening heart failure symptoms, particularly in those relying on acetyldigitoxin for rate control or inotropic support."
"The risk or severity of adverse effects can be increased when Pimecrolimus is combined with Cladribine."
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about MEXATE-AQ vs CLADRIBINE, answered by our medical review team.
MEXATE-AQ is a Antineoplastic Agent that works by Methotrexate is a folate analog that inhibits dihydrofolate reductase (DHFR), blocking the conversion of dihydrofolate to tetrahydrofolate, which is required for the synthesis of purines and pyrimidines. This leads to inhibition of DNA, RNA, and protein synthesis, particularly in rapidly dividing cells. It also has immunosuppressive effects via inhibition of T cell activation and reduction of inflammatory cytokines.. CLADRIBINE is a Antineoplastic Agent that works by Cladribine is a purine nucleoside analog that is phosphorylated intracellularly to its active triphosphate form, which inhibits DNA synthesis and repair, leading to cell death, particularly in lymphocytes. It also depletes adenosine deaminase (ADA) and accumulates in cells with high deoxycytidine kinase activity.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between MEXATE-AQ and CLADRIBINE depend on the specific clinical indication. These are both Antineoplastic Agent agents and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of MEXATE-AQ is: Methotrexate: 7.5-25 mg orally once weekly for rheumatoid arthritis; 30-40 mg/m2 IV weekly for mycosis fungoides; 50-75 mg/m2 IV over 4-6 hours weekly for osteosarcoma; 15-20 mg/m2 IM weekly for psoriasis.. The standard adult dose of CLADRIBINE is: 0.09 mg/kg/day IV over 2 hours for 7 consecutive days; or 0.14 mg/kg/day IV over 2 hours for 5 consecutive days (total dose 0.7 mg/kg per course).. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between MEXATE-AQ and CLADRIBINE in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. MEXATE-AQ is classified as Category C. FDA Pregnancy Category X. First trimester: High risk of miscarriage, CNS defects, craniofacial anomalies. Second trimester: IUGR, skeletal abnormalities. Third trimester: Neonatal . CLADRIBINE is classified as Category C. FDA Pregnancy Category D. First trimester: Avoid due to known teratogenicity in animal studies (skeletal and visceral malformations) and potential for MDS and AML. Second and third. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.