It is not to be confused with O=C([C@H](CCC(O)=O)NC(C1=CC=C(N(CC2=CN=C(N=C(N)N=C3N)C3=N2)C)C=C1)=O)OInChI=1S/C20H22N8O5/c1-28(9-11-8-23-17-15(24-11)16(21)26-20(22)27-17)12-4-2-10(3-5-12)18(31)25-13(19(32)33)6-7-14(29)30/h2-5,8,13H,6-7,9H2,1H3,(H,25,31)(H,29,30)(H,32,33)(H4,21,22,23,26,27)/t13-/m0/s1 In treating rheumatoid arthritis with methotrexate, the possibility of increased toxicity with concomitant use of NSAIDs including salicylates has not been fully explored. Concomitant use of PPIs and high-dose methotrexate should be avoided especially in patients with renal impairment.

Manufacturer advises use with caution or avoid. {* traditionalSignIn_emailAddress *} ©2020 Pfizer. {* acknowledgement_consent *} {* #postLoginAcceptanceForm *} {* traditionalSignIn_emailAddress *} The information is not intended as medical advice.Site is intended for CA residents. {* designation_specialty *}

{* traditionalSignIn_signInButton *} {* traditionalRegistration_passwordConfirm *} Preliminary animal and human studies have shown that small quantities of intravenously administered leucovorin enter the cerebrospinal fluid primarily as 5-methyl tetrahydrofolate and, in humans, remain 1 to 3 orders of magnitude lower than the usual methotrexate concentrations following intrathecal administration. Pfizer recognizes the public concern in relation to COVID-19, which continues to evolve. {* salutation *} Combination of Methotrexate Injection USP and mercaptopurine may therefore require dose adjustment.Vitamin preparations containing folic acid or its derivatives may decrease responses to methotrexate. {* socialRegistration_lastName *} Therefore, patients receiving concomitant therapy with Methotrexate Injection USP and other potential hepatotoxic agents (e.g., leflunomide, azathioprine, sulfasalazine, retinoids) should be closely monitored for possible increased risk of hepatotoxicity.Methotrexate given concomitantly with IV cytarabine may increase the risk of severe neurologic adverse events such as headache, paralysis, coma and stroke-like episodes (see Combined use of methotrexate with other cytotoxic agents has not been studied and may increase the incidence of adverse effects.The effects of herbal products on the pharmacokinetics of methotrexate have not been studied.Interactions with laboratory tests have not been established.Use of alcohol with Methotrexate Injection USP is contraindicated (see Some of the effects (e.g., dizziness and fatigue) may have an influence on the ability to drive or operate machinery.To report an adverse event (or suspected side-effect) experienced with a Pfizer medication (prescription, no-prescription or a vaccine) please contact us at For all information related to our products, please consult the patient information brochure and the Product Monograph, which are available at This site is intended to provide answers to unsolicited medical questions.

To access full product monograph, However, hepatotoxicity has been reported in such cases. Methotrexate clearance is decreased by cisplatinum.Although not documented, other nephrotoxic drugs such as aminoglycosides, Amphotericin B and Cyclosporin could theoretically increase methotrexate toxicity by decreasing its elimination.The use of nitrous oxide anesthesia potentiates the effect of methotrexate on folate metabolism, yielding increased toxicity such as severe, unpredictable myelosuppression, stomatitis, neurotoxicity (with intrathecal administration of methotrexate) and nephritis (see Penicillins and sulfonamides may reduce the renal clearance of methotrexate; hematologic and gastrointestinal toxicity have been observed in combination with methotrexate. Concurrent use of the anti-protozoal Methotrexate may decrease the clearance of theophylline; theophylline levels should be monitored when used concurrently with Methotrexate Injection USP.Methotrexate increases the plasma levels of mercaptopurine.

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Your login attempt failed. Methotrexate is used to treat certain types of cancer of the breast, skin, head and neck, or lung. [Preston, 2016; ABPI, 2017a; BNF 75, 2018] Pregnancy and breastfeeding.