{"id":4193,"date":"2025-03-31T18:12:00","date_gmt":"2025-03-31T18:12:00","guid":{"rendered":"https:\/\/kidneydiseaseclinic.net\/kdc\/methotrexate-txt\/"},"modified":"2025-03-31T18:12:00","modified_gmt":"2025-03-31T18:12:00","slug":"methotrexate-txt","status":"publish","type":"post","link":"https:\/\/kidneydiseaseclinic.net\/kdc\/methotrexate-txt\/","title":{"rendered":"Methotrexate.txt"},"content":{"rendered":"

CLINICAL USE <\/H3>
\nAntineoplastic agent:Severe rheumatoid arthritis Severe uncontrolled psoriasis Crohn\u2019s disease Neoplastic disease

DOSE IN NORMAL RENAL FUNCTION <\/H3>Rheumatoid arthritis: Oral, SC, IM, IV: 7.5\u201320 mg once a weekPsoriasis: (Oral) 10\u201325 mg once weekly, adjusted to responseCrohn\u2019s disease: 15\u201325 mg weekly Neoplastic disease: Dose by weight or surface area according to specific indication

PHARMACOKINETICS <\/H3>
  • Molecular weight &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp :454.4<\/li>\n
  • %Protein binding &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp :45\u201360<\/li>\n
  • %Excreted unchanged in urine &nbsp &nbsp : 80\u201390<\/li>\n

  • Volume of distribution (L\/kg) &nbsp &nbsp &nbsp :0.4\u20130.8<\/li>\n

  • half-life \u2013 normal\/ESRD (hrs)&nbsp &nbsp &nbsp :2\u201317\/Increased

    DOSE IN RENAL IMPAIRMENT <\/H3>

    GFR (mL\/MIN)<\/H4>
  • 20 to 50 &nbsp &nbsp : 50\u2013100% of normal dose
  • 10 to 20 &nbsp &nbsp : 50% of normal dose
  • <10 &nbsp &nbsp &nbsp &nbsp &nbsp : <\/p>\n
  • Contraindicated

    DOSE IN PATIENTS UNDERGOING RENAL REPLACEMENT THERAPIES <\/H3>
  • CAPD &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp:Not dialysed.\n
  • Contraindicated\n
  • HD &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp :Dialysed. Haemodialysis clearance is 38\u201340 mL\/minute. 50% of normal dose at least 12 hours before next dialysis. Use with caution
  • HDF\/high flux &nbsp :Dialysed. 50% of normal dose at least 12 hours before next dialysis. Use with caution
  • CAV\/VVHD &nbsp &nbsp &nbsp:Unknown dialysability. Dose as in GFR 10 to 20 mL\/min

    IMPORTANT DRUG INTERACTIONS <\/H3>Potentially hazardous interactions with other drugs\n
  • Anaesthetics: antifolate effect increased by nitrous oxide \u2013 avoid concomitant use\n
  • Analgesics: increased risk of toxicity with NSAIDs\n
  • Antibacterials: absorption possibly reduced by neomycin; antifolate effect increased with co-trimoxazole and trimethoprim; penicillins and possibly ciprofloxacin reduce excretion of methotrexate (increased risk of toxicity); increased haematological toxicity with doxycycline and tetracycline\n
  • Antimalarials: antifolate effect enhanced by pyrimethamine\n
  • Antipsychotics: avoid concomitant use with clozapine (increased risk of agranulocytosis)\n
  • Ciclosporin: methotrexate may inhibit the clearance of ciclosporin or its metabolites; ciclosporin may inhibit methotrexate eliminationCorticosteroids: increased risk of haematological toxicityCytotoxics: increased pulmonary toxicity with cisplatinProbenecid: excretion of methotrexate reduced\n
  • Retinoids: concentration increased by acitretin, also increased hepatotoxicity \u2013 avoid concomitant use

    ADMINISTRATION <\/H3>

    Reconstition<\/H4>Compatible with glucose 5%, sodium chloride 0.9%, compound sodium lactate, or Ringers solution

    Route <\/H4>Oral, IM, IV (bolus injection or infusion), intrathecal, intra-arterial, intraventricular

    Rate of Administration <\/H4>Slow IV injection

    Comments<\/H4>High-dose methotrexate may cause precipitation of methotrexate or its metabolites in renal tubules. A high fluid throughput and alkalinisation of urine, using sodium bicarbonate if necessary, is recommended.470 METhoTrEXATE

    OTHER INFORMATION <\/H4>The dose is well absorbed at doses 90%), although small amounts via the bile. Clearance is higher in children than in adultsCalcium folinate (calcium leucovorin) is a potent agent for neutralising the immediate toxic effects of methotrexate on the haematopoietic systemCalcium folinate rescue may begin 24\/32\/36 hours post start of methotrexate therapy, according to local protocol. Doses of up to 120 mg may be given over 12\u201324 hours by IM or IV injection or infusion, followed by 12\u201315 mg IM, or 15 mg orally every 6 hours for the next 48 hoursRenal function should be closely monitored throughout treatmentAn approximate correction for renal function may be made by reducing the dose in proportion to the reduction in creatinine clearance based on a normal creatinine clearance of 60 mL\/minute\/m2Alternative dosing regimen: CrCl (mL\/min) Dose>80 100%60 65%45 50%<30 AvoidDoses in renal failure from Kintzel PE, Dorr RT. Anticancer drug renal toxicity and elimination: dosing guidelines for altered renal function.
    \n","protected":false},"excerpt":{"rendered":"

    CLINICAL USE Antineoplastic agent:Severe rheumatoid arthritis Severe uncontrolled psoriasis Crohn\u2019s<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[7],"class_list":["post-4193","post","type-post","status-publish","format-standard","hentry","category-blog","tag-post-by-auto-php"],"_links":{"self":[{"href":"https:\/\/kidneydiseaseclinic.net\/kdc\/wp-json\/wp\/v2\/posts\/4193","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kidneydiseaseclinic.net\/kdc\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kidneydiseaseclinic.net\/kdc\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kidneydiseaseclinic.net\/kdc\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/kidneydiseaseclinic.net\/kdc\/wp-json\/wp\/v2\/comments?post=4193"}],"version-history":[{"count":0,"href":"https:\/\/kidneydiseaseclinic.net\/kdc\/wp-json\/wp\/v2\/posts\/4193\/revisions"}],"wp:attachment":[{"href":"https:\/\/kidneydiseaseclinic.net\/kdc\/wp-json\/wp\/v2\/media?parent=4193"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kidneydiseaseclinic.net\/kdc\/wp-json\/wp\/v2\/categories?post=4193"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kidneydiseaseclinic.net\/kdc\/wp-json\/wp\/v2\/tags?post=4193"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}