Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
FOLEX PFS vs AGRYLIN
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 synthesis of tetrahydrofolate and thereby interfering with DNA synthesis, repair, and cellular replication. It also exhibits immunosuppressive and anti-inflammatory effects through inhibition of purine and pyrimidine synthesis and reduction of cytokine production.
Agrylin (anagrelide) inhibits cyclic nucleotide phosphodiesterase III (PDE3) and reduces platelet production by interfering with megakaryocyte maturation and proliferation, likely via inhibition of cyclic AMP phosphodiesterase and modulation of intracellular calcium levels.
Neoplastic diseases: gestational choriocarcinoma, chorioadenoma destruens, hydatidiform mole, acute lymphocytic leukemia, meningeal leukemia, breast cancer, head and neck cancer, advanced mycosis fungoides, lung cancer (especially squamous cell and small cell types), advanced non-Hodgkin's lymphomas.,Psoriasis (severe, recalcitrant, disabling, not adequately responsive to other therapy),Rheumatoid arthritis (active, severe, refractory to first-line therapy),Off-label uses: ectopic pregnancy, sarcoidosis, inflammatory bowel disease (Crohn's disease), vasculitis, systemic lupus erythematosus, dermatomyositis, juvenile idiopathic arthritis, graft-versus-host disease, multiple sclerosis, polymyositis, acute graft rejection prophylaxis
Essential thrombocythemia (ET) to reduce elevated platelet counts and the risk of thrombotic complications
Methotrexate 30-40 mg/m2 IV once weekly or 7.5-15 mg PO once weekly as single dose or divided into 3 doses over 24 hours.
Adults: 0.5 mg orally once or twice daily, increased by 0.5 mg every 2 weeks to maintain platelet count <600,000/µL. Maximum dose: 10 mg/day.
Terminal elimination half-life: 6-12 hours in patients with normal renal function. With impaired renal function, half-life is prolonged (up to 24-48 hours). Low-dose methotrexate (e.g., for rheumatoid arthritis) has half-life 3-10 hours. High-dose methotrexate has a triphasic elimination: alpha phase (0.75 hours), beta phase (3.5 hours), and terminal gamma phase (10-20 hours).
Terminal elimination half-life: 1.3–1.5 days (31–36 hours) in patients with ET; allows twice-daily dosing.
Methotrexate undergoes hepatic and intracellular metabolism to polyglutamated forms which are retained for prolonged periods. The primary metabolic pathway involves conversion to 7-hydroxymethotrexate by aldehyde oxidase. Renal excretion is the major route of elimination, with approximately 80-90% of the dose excreted unchanged in the urine within 24 hours. Enterohepatic recirculation occurs. Biliary excretion accounts for a minor fraction.
Primarily metabolized by CYP1A2 to the active metabolite 3-hydroxyanagrelide, and to a lesser extent by CYP2C19 and CYP2D6.
Primarily renal excretion as unchanged drug; approximately 80-90% excreted unchanged in urine within 24 hours. Biliary/fecal excretion is minimal (<10%).
Renal: 80% (primarily unchanged drug), Biliary/Fecal: 5%
Approximately 50% bound to serum albumin, primarily to albumin. Binding is saturable at high doses.
82–88% bound to plasma proteins (primarily albumin).
Volume of distribution: 0.4-0.8 L/kg (40-80 L/70 kg). Higher doses may increase Vd due to tissue binding. Distributes into third-space fluids, including pleural effusions and ascites.
30–36 L (approximately 0.45–0.5 L/kg for a 70 kg adult); indicates extensive tissue distribution.
Oral: 60-70% (dose-dependent, saturable absorption). IM: 76-100% relative to IV. IV: 100%.
Oral: 65–80% (median 73%)
Cr Cl 30-60 m L/min: reduce dose by 30-50%; Cr Cl <30 m L/min: avoid use or use extreme caution with dose reduction >50%.
No specific GFR-based recommendations; use with caution in renal impairment (Cr Cl <50 m L/min) and monitor closely.
Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50%; Child-Pugh C: avoid use.
Child-Pugh A: No adjustment. Child-Pugh B or C: Reduce initial dose by 50% and titrate cautiously.
Juvenile idiopathic arthritis: 10-15 mg/m2 IV/IM once weekly; leukemia maintenance: 15-30 mg/m2 PO/IM once weekly.
Children ≥7 years: 0.5 mg orally once or twice daily; adjust based on platelet response. Maximum: 10 mg/day. Not established for <7 years.
Start at lower end of dosing range (e.g., 7.5-10 mg once weekly) due to reduced renal and hepatic function; monitor for myelosuppression and mucositis.
No specific adjustment; start at lower end of dosing range (0.5 mg twice daily) and monitor renal function and platelet counts closely.
WARNING: METHOTREXATE SHOULD BE USED ONLY BY PHYSICIANS EXPERIENCED IN ANTIMETABOLITE THERAPY. DEATHS HAVE BEEN REPORTED WITH THE USE OF METHOTREXATE IN THE TREATMENT OF MALIGNANCY, PSORIASIS, AND RHEUMATOID ARTHRITIS. PATIENTS SHOULD BE CLOSELY MONITORED FOR BONE MARROW SUPPRESSION, HEPATOTOXICITY, PULMONARY TOXICITY, AND RENAL TOXICITY. METHOTREXATE IS CONTRAINDICATED IN PREGNANCY AND LACTATION. DOSING FOR NON-NEOPLASTIC DISEASES (PSORIASIS AND RHEUMATOID ARTHRITIS) IS ONCE WEEKLY; DAILY DOSING HAS LED TO FATAL TOXICITY. ACCIDENTAL OVERDOSAGE HAS RESULTED IN FATALITIES.
None
Bone marrow suppression: leukopenia, thrombocytopenia, anemia, pancytopenia,Hepatotoxicity: acute hepatitis, hepatic fibrosis, cirrhosis (especially with chronic use),Pulmonary toxicity: pneumonitis, interstitial alveolitis, pulmonary fibrosis,Renal toxicity: nephropathy, renal failure (due to precipitation of methotrexate and its metabolites in the renal tubules),Gastrointestinal toxicity: ulcerative stomatitis, diarrhea, hemorrhagic enteritis,Infections: increased risk of opportunistic infections (e.g., Pneumocystis jirovecii pneumonia),Dermatologic reactions: photosensitivity, Stevens-Johnson syndrome,Neurologic effects: encephalopathy, seizures, headache,Monitoring: baseline and periodic complete blood counts, liver function tests, renal function tests, chest X-ray,Methotrexate elimination is impaired in patients with renal impairment, ascites, or pleural effusions, leading to increased toxicity,Concurrent use of NSAIDs may increase methotrexate toxicity
Cardiovascular risks: increased risk of ventricular tachycardia, QTc prolongation, and heart failure; use caution in patients with known cardiac disease.,Hematologic effects: monitor complete blood counts regularly due to risk of anemia, leukopenia, or thrombocytopenia.,Hepatic impairment: reduce dose in patients with moderate to severe hepatic impairment.,Renal impairment: use with caution in severe renal impairment.
Pregnancy and lactation (FDA Pregnancy Category X),Severe renal impairment (e GFR < 30 m L/min/1.73 m²),Severe hepatic impairment (cirrhosis, active hepatitis),Alcoholism or alcoholic liver disease,Pre-existing blood dyscrasias (e.g., bone marrow hypoplasia, severe anemia, leukopenia, thrombocytopenia),Active immunodeficiency syndromes (e.g., AIDS),Hypersensitivity to methotrexate or any component of the formulation,Concurrent treatment with live vaccines,Breastfeeding
Severe hepatic impairment,Known hypersensitivity to anagrelide or any component of the formulation
Foods high in folate (e.g., dark leafy greens, beans, liver) may theoretically reduce methotrexate efficacy; however, patients are often given folic acid supplements to mitigate toxicity. Caffeine may interfere with methotrexate clearance; avoid excessive caffeine intake (e.g., >4 cups coffee/day). Grapefruit and grapefruit juice may increase methotrexate levels via CYP inhibition; avoid concurrent consumption. Alcohol consumption during methotrexate therapy significantly increases risk of hepatocellular injury and is contraindicated. Avoid folic acid-fortified foods (e.g., enriched cereals, breads) in large amounts unless supplementing under medical direction.
Grapefruit and grapefruit juice should be avoided as they may increase anagrelide plasma concentrations. No other specific dietary restrictions; however, maintain adequate hydration to reduce risk of crystalluria.
FDA Pregnancy Category X. First trimester: severe teratogenic effects including neural tube defects, craniofacial anomalies, and limb defects. Second trimester: increased risk of fetal growth restriction, oligohydramnios, and fetal loss. Third trimester: neonatal myelosuppression, immunosuppression, and acute renal failure.
Pregnancy Category C. Anagrelide is not recommended in pregnancy. Animal studies have shown embryotoxicity and teratogenicity (e.g., increased fetal resorptions, skeletal anomalies) at doses less than the human therapeutic dose. There are no adequate and well-controlled studies in pregnant women. Use only if potential benefit justifies potential risk to fetus. First trimester: Avoid due to organogenesis risk. Second and third trimesters: Unknown risks; consider alternative therapy.
Contraindicated in breastfeeding. Methotrexate is excreted in human milk and can accumulate in neonatal tissues. M/P ratio not established but reported to be 0.08:1 in limited data.
It is not known whether anagrelide is excreted in human milk. No M/P ratio is available. Due to potential for serious adverse reactions in breastfed infants (e.g., thrombocytopenia, cardiovascular effects), advise women not to breastfeed during treatment and for at least 7 days after last dose.
Not applicable; contraindicated in pregnancy. If inadvertent exposure occurs, immediate discontinuation is advised. Folinic acid rescue may be considered in first trimester exposure.
No specific pharmacokinetic studies in pregnancy. Pregnancy-induced plasma volume expansion may lower drug concentrations, potentially requiring dose adjustment to maintain therapeutic effect. However, due to teratogenicity risks, avoid use in pregnancy. If necessary, start at lowest effective dose (0.5 mg/day) and titrate based on platelet count monitoring, not to exceed 10 mg/day.
Methotrexate (FOLEX PFS) is a folate analog antimetabolite; always confirm dose and route as intrathecal use has high risk of neurotoxicity. Leucovorin rescue is mandatory after high-dose methotrexate (typically >500 mg/m²) to prevent severe myelosuppression and mucositis. Monitor renal function closely as methotrexate is primarily renally excreted; accumulation can cause acute kidney injury. Hydration and urine alkalinization (target urine p H >7) enhance excretion and reduce nephrotoxicity. Avoid concurrent use of NSAIDs and weak acids (e.g., aspirin, penicillin) as they decrease renal clearance. Intrathecal administration carries risk of chemical arachnoiditis, seizures, and leukoencephalopathy; assess for neurotoxicity symptoms after dosing. Methotrexate can cause pneumonitis; rule out infection if new respiratory symptoms develop.
Agrylin (anagrelide) is a phosphodiesterase III inhibitor used to reduce platelet counts in essential thrombocythemia. Monitor platelet count weekly during titration; target <600,000/µL. Avoid in patients with severe hepatic impairment (Child-Pugh C). Use with caution in cardiac disease due to risk of QT prolongation and arrhythmias. Anagrelide may increase bleeding risk, especially when combined with anticoagulants or NSAIDs. Discontinue 4-5 days before elective surgery.
Take methotrexate exactly as prescribed; do not change dose or frequency without consulting your doctor.,Avoid alcohol completely during treatment to reduce risk of hepatotoxicity.,Drink plenty of fluids (aim for 2-3 liters daily) to prevent kidney damage.,Notify your healthcare provider immediately if you develop mouth sores, fever, chills, sore throat, easy bruising/bleeding, shortness of breath, or yellowing of skin/eyes.,Women of childbearing potential must use effective contraception during treatment and for at least 3 months after last dose; methotrexate is teratogenic.,Do not take any over-the-counter pain relievers (especially NSAIDs like ibuprofen, naproxen) without clearance, as they increase toxicity risk.,Folic acid supplementation may be prescribed to reduce side effects; take it exactly as directed.,Avoid live vaccines while on treatment and for 3 months after discontinuation.,Limit sun exposure and use sunscreen as methotrexate may increase photosensitivity.
Take exactly as prescribed; do not skip doses or double up.,Report any signs of bleeding (easy bruising, nosebleeds, black/tarry stools) or palpitations immediately.,Avoid NSAIDs like ibuprofen and aspirin unless directed by your doctor.,Do not consume grapefruit or grapefruit juice while taking this medication.,Inform all healthcare providers (including dentists) that you are on anagrelide.,Store at room temperature away from moisture and heat.
No interactions on record
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about FOLEX PFS vs AGRYLIN, answered by our medical review team.
FOLEX PFS is a Antineoplastic Agent that works by Methotrexate is a folate analog that inhibits dihydrofolate reductase (DHFR), blocking the synthesis of tetrahydrofolate and thereby interfering with DNA synthesis, repair, and cellular replication. It also exhibits immunosuppressive and anti-inflammatory effects through inhibition of purine and pyrimidine synthesis and reduction of cytokine production.. AGRYLIN is a Antineoplastic Agent that works by Agrylin (anagrelide) inhibits cyclic nucleotide phosphodiesterase III (PDE3) and reduces platelet production by interfering with megakaryocyte maturation and proliferation, likely via inhibition of cyclic AMP phosphodiesterase and modulation of intracellular calcium levels.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between FOLEX PFS and AGRYLIN 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 FOLEX PFS is: Methotrexate 30-40 mg/m2 IV once weekly or 7.5-15 mg PO once weekly as single dose or divided into 3 doses over 24 hours.. The standard adult dose of AGRYLIN is: Adults: 0.5 mg orally once or twice daily, increased by 0.5 mg every 2 weeks to maintain platelet count <600,000/µL. Maximum dose: 10 mg/day.. 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 FOLEX PFS and AGRYLIN 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. FOLEX PFS is classified as Category C. FDA Pregnancy Category X. First trimester: severe teratogenic effects including neural tube defects, craniofacial anomalies, and limb defects. Second trimester: increased risk of f. AGRYLIN is classified as Category C. Pregnancy Category C. Anagrelide is not recommended in pregnancy. Animal studies have shown embryotoxicity and teratogenicity (e.g., increased fetal resorptions, skeletal anomalies. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.