Methotrexate injection dose

The injection is available in 25mg/ml or 50mg/2ml vials. The usual dose is 7.5mg to 25mg per week. Methotrexate may be injected just under the skin or intramuscularly. Follow your rheumatologist's directions dose therapy. Methotrexate Injection, USP Isotonic Liquid, Contains Preservative is available in 25 mg/mL, 2 mL (50 mg) vials. Each 25 mg/mL, 2 mL vial contains methotrexate sodium equivalent to 50 mg methotrexate, 0.9% w/v of Benzyl Alcohol as a preservative, and the following inactive ingredients: Sodiu In low doses, methotrexate is applied within the scope of complex therapy protocols for maintaining remission in adults with acute lymphocytic leukaemias. Normal single doses lie within the range of 20-40 mg/m 2 methotrexate. The maintenance dose for ALL is 15-30 mg/m 2 once or twice weekly If peak serum methotrexate <454 mcg/mL at end of initial infusion, dose may be increased to 15 g/m 2 in subsequent treatments Not to exceed 20 g/dose Administer leucovorin rescue in accordance with.. Oral methotrexate 3.3 mg/m 2 daily, and prednisolone 40-60 mg/m 2 daily for 4-6 weeks has been used. After a remission is attained, methotrexate in a maintenance dosage of 20-30 mg/m 2 orally or by I.M. injection has been administered twice weekly. Twice weekly doses appear to be more effective than daily drug administration

This 2-dose protocol minimizes the number of injections and surveillance visits, compared with the multiple dose regimen, and methotrexate is administered more frequently than with the single dose regimen. The protocol may optimize the balance between convenience and efficacy. In a limited num Methotrexate Injection, USP is sterile and non-pyrogenic and may be given by the intramuscular, intravenous or intra-arterial route. (See DOSAGE AND ADMINISTRATION.) The preserved formulation contains benzyl alcohol; do not use for intrathecal or high-dose therapy. Methotrexate Injection, USP, Isotonic Liquid, Preservative Free, for single-dose only, is available in 25 mg/mL, 2 mL (50 mg), 4. Folinic acid can be given orally, IM or IV inj starting 24 hr after the beginning of the methotrexate infusion. Give via parenteral routes If patient experiences GI toxicity (e.g., nausea, vomiting). Usual dosage of folinic acid: 15 mg every 6 hr for a total of 60 hr or a total of 10 doses What is the typical dose for methotrexate? Most rheumatologists will dose methotrexate between 15mg and 25mg. In some cases, the dose may be higher or lower based on the condition being treated and other factors related to the individual patient's disease or other medical conditions. It is only taken one day per week The usual adult dose of methotrexate for rheumatoid arthritis is, as mentioned above, 7.5 milligrams as a single weekly dose. 1  It can be taken as a divided dose: 2.5 milligrams taken orally every 12 hours for 3 divided doses over 36 hours once a week

You must use the correct dose for your condition. Methotrexate can cause serious or fatal side effects. Tell your doctor if you have diarrhea , mouth sores, cough, shortness of breath, upper stomach pain, dark urine, numbness or tingling, muscle weakness, confusion, seizure, or skin rash that spreads and causes blistering and peeling • Use another formulation of methotrexate for patients requiring oral, intramuscular, intravenous, intra -arterial, or intrathecal dosing, doses less than 10 mg per week, doses above 25 mg per week, high-dose regimens, or dose adjustments of less than 5 mg increments (2.1) • Starting doses of methotrexate: • RA: 7.5 mg once weekly (2.2 For rheumatic conditions, methotrexate is taken as pills or a subcutaneous injection, usually once per week. Methotrexate is considered an antiproliferative medication, which means it stops cells from replicating. It reduces the activity of several types of proteins and cells involved in immune system function, including T cells and B cells

Methotrexate treatment of unruptured ectopic pregnancy is safe and effective and preserves reproductive potential. Previous protocols have required multiple methotrexate doses with or without citrovorum rescue. The purpose of this study was to determine whether patients with an unruptured ectopic pr Methotrexate Injections. Your provider has prescribed that you receive methotrexate by injection. This handout explains the drug, its side effects, drug interactions, and how to give yourself a subcutaneous injection of methotrexate. What is methotrexate? Methotrexate is a medicine used to treat chronic conditions such as arthritis We are open for safe in-person care. Learn more: Mayo Clinic facts about coronavirus disease 2019 (COVID-19) Our COVID-19 patient and visitor guidelines, plus trusted health information Latest on COVID-19 vaccination by site: Arizona patient vaccination updates Arizona, Florida patient vaccination updates Florida, Rochester patient vaccination updates Rochester and Mayo Clinic Health System.

Injectable Methotrexate is a clear yellow liquid. It is dispensed by your Pharmacist in small 2 mL vials which contain less than ½ teaspoonful of methotrexate. Here are some important features of the vials of methotrexate: For patients with inflammatory arthritis, methotrexate is supplied as 50 mg in a 2 mL vial (25 mg per 1 mL) Always follow the instructions from your doctor. For rheumatoid arthritis, the usual starting dose is 7.5mg, taken once a week. This can be slowly increased up to 20mg (tablets) or 25mg (pre-filled injection pen or syringe) once a week. For psoriasis, the usual starting dose is 2.5mg to 10mg, taken once a week

Methotrexate Injection • Johns Hopkins Arthritis Cente

Methotrexate Injection prescription and dosage sizes information for physicians and healthcare professionals. Pharmacology, adverse reactions, warnings and side effects Methotrexate for Injection prescription and dosage sizes information for physicians and healthcare professionals. Pharmacology, adverse reactions, warnings and side effects For central nervous system-directed therapy, a recommended dosage of Methotrexate Injection is 8,000 mg/m 2 as an intravenous infusion over 4 hours as a single agent or in combination with immunochemotherapy at doses ranging from 3,000 mg/m 2 to 8,000 mg/m 2 followed by leucovorin rescue in accordance with high-dose methotrexate regimen. SELF INJECTING LOW DOSE METHOTREXATE FOR THE TREATMENT OF ARTHRITIS (Brand names: Hospira, Methacord, Methotrexate Accord, Trexject) This sheet is useful if your doctor has recommended injections of methotrexate either for better efficacy or to reduce side-effects. It gives information about how you, or a friend or family member Background/Purpose: Methotrexate (MTX) is the cornerstone of rheumatoid arthritis (RA) therapy1 but absorption saturation limitations compromise oral MTX bioavailability (BA). Subcutaneous (SC) MTX has a dose-proportional, linear absorption profile compared to oral MTX, which plateaus at doses >15 mg.2 Differences in the relative BA of oral vs SC MTX demonstrate the need for guidance on [

Methotrexate 25 mg/ml solution for injection - Summary of

Trexall, Otrexup (methotrexate) dosing, indications

  1. These syringes have numbers written along their side to help you draw up the correct amount of liquid for the dose of methotrexate you are taking. They can be bought in bags of 10 at the pharmacy. You should have a sharps container for disposing of the syringe after the injection; this can be obtained from pharmacies
  2. Withhold methotrexate until discussed with specialist team. Folic acid mouth wash may help with mucositis. Nausea and vomiting, diarrhoea: Dividing the dose over the day or giving methotrexate by subcutaneous injection is often a good way of avoiding nausea. New or increasing dyspnoea or dry cough (pneumonitis
  3. imum dose of 5mg folic acid once weekly
  4. When treating severe psoriasis, you usually take methotrexate once per week as an oral tablet or injectable solution. The typical starting dose is 10 to 25 milligrams (mg)
  5. istered by IV infusion, the total dose is diluted in 5% dextrose solution, USP.1 For intrathecal injection, reconstitute to a concentration of 1 mg/mL with an appropriate sterile, preservative free medium such as sodium chloride injection, USP.
  6. 1 mL of solution for injection contains 20 mg methotrexate (as 21.94 mg methotrexate disodium). 1 pre-filled syringe of 0.375 mL solution for injection contains 7.5 mg methotrexate. 1 pre-filled syringe of 0.5 mL solution for injection contains 10 mg methotrexate. 1 pre-filled syringe of 0.625 mL solution for injection contains 12.5 mg.

Even low-dose methotrexate can cause harm or death if taken daily or with certain other medicines Methotrexate is a medicine used to treat certain types of cancer. Doctors also prescribe methotrexate to treat other conditions such as severe rheumatoid arthritis and psoriasis (a skin condition) Emergency Gynecologic Methotrexate Kit. This opens in a new window. The Emergency Gynecologic Methotrexate injection ( mtx injection) from Edge Pharma solves a major issue affecting hospitals and OB/GYN clinics. In facilities without a USP 800 compliant hazardous cleanroom, preparation and administration of Methotrexate is a challenge

Methotrexate 100 mg/ml Injection - Summary of Product

  1. This is sometimes called methotrexate fog, and can occur a day after receiving a dose of methotrexate (which is taken in pill form or injected once a week). Hair loss is a relatively uncommon side effect in people who take methotrexate at arthritis-relieving doses
  2. Methotrexate may cause very serious, life-threatening side effects. Talk to your doctor about the risks of receiving methotrexate injection for your condition. Methotrexate injection may cause a serious, life-threatening reaction that may occur while or shortly after you receive this medication
  3. Methotrexate comes as tablets (2.5mg and 10mg strengths), liquid, injection and pre-filled injection pens and syringes. Maxtrex is a brand name for methotrexate tablets
  4. Drug Name Generic Name : methotrexate (methopterin, MTX) Brand Name: Apo-Methotrexate (CAN), ratio-Methotrexate (CAN), Rheumatrex, Rheumatrex Dose Padk, Trexall Classification: Antimetabolite, Antineoplastic, Antipsoriatic, Antirheumatic Pregnancy Category X Dosage & Route Available forms : Tablets—2.5, 5, 7.5, 10, 15 mg; powder for injection—20 mg, 1 g per vial; injection—25 mg/mL.

It is common for patients with rheumatoid arthritis and other rheumatic diseases to be prescribed methotrexate as part of their treatment. This video demons.. Purpose: High‐dose methotrexate (HD‐MTX)-based chemotherapy regimen is the first-line treatment of primary central nervous system lymphoma (PCNSL). At present, doses of MTX in the range of 3.5- 8 g/m 2 are frequently used. However, the optimal dose of methotrexate for PCNSL remains controversial Methotrexate is an antineoplastic and immunosuppressive agent widely used in the therapy of leukemia, lymphoma, solid tumors, psoriasis and rheumatoid arthritis. When given in high intravenous doses, methotrexate can cause acute elevations in serum enzymes, and long term methotrexate therapy has been associated with frequent but mild elevations in serum liver enzymes and, more importantly. Just took my second dose of Methotrexate. All 3 pills at once.. as I was instructed by my Rheumatologist. My mouth sores only just went away this afternoon but they might come back tomorrow. Also had a painful horrible steroid injection in my shoulder earlier. Let's hope that helps too Injection: Methotrexate 2/11. Some products have benzyl alcohol. These products must not be given to a newborn or infant. These products may also not be right for some other people. so could lead to the dose being too high. Injection (subcutaneous):,.

The dose of methotrexate will be different for different people. Your doctor will calculate your dose based on your condition, your blood test results and your response. If methotrexate is being used for arthritis or psoriasis, it is usually taken once a week (every 7 days) as it lasts in your body much longer than most other medicines I didn't take the folic acid and just resumed a week later when I was back onto the methotrexate. For me it was noticeable within the week in terms of joint pain. In fact my Rheumatoligist recently changed me to self injections and dropped the dose by 5mg, and within three weeks there has been a very clear change in my CRP levels (upwards) and. oral methotrexate (po MTX) 15 mg weekly oral methotrexate + placebo injection; sq methotrexate (sq MTX) 15 mg weekly sq methotrexate + oral placebo; Subjects were continued on stable background NSAIDs and low-dose prednisone. Folic acid was administered to all subjects at a dose of 5 mg per week

Use of 2-dose regimen of methotrexate to treat ectopic

Methotrexate injection may be further diluted in 0.9% Sodium Chloride Injection. High doses of methotrexate administered by IV infusion may be diluted in 5% Dextrose Injection. Storage of methotrexate containing benzyl alcohol: After dilution, methotrexate should be used within 4 hours at room temperature (20 to 25 degrees C) or within 24 hours. [X] Administer calculated methotrexate dose Routine, Once, Starting today For 1 Occurrences, Give IM and Follow chemotherapy precautions for safe handling [ ] methotrexate (ECTOPIC PREGNANCY) injection 1 mg/kg, IntraMuscular, Once, For 1 Doses, Routine Indications: Ectopic pregnanc Methotrexate is used to treat leukemia and certain types of cancer of the breast, skin, head and neck, or lung.. Methotrexate is also used to treat severe psoriasis and rheumatoid arthritis in adults, and to treat active polyarticular-course juvenile rheumatoid arthritis in children.. Methotrexate is often used when other medicines have not been effective..

METHOTREXATE INJECTION, USP 50 mg/2 mL (25 mg/mL), 250 mgMethotrexate Manufacturers & OEM Manufacturer in India

Methotrexate Injection, US

  1. Methotrexate injection is also used along with rest, physical therapy and sometimes other medications to treat severe active rheumatoid arthritis (RA; a condition in which the body attacks its own joints, causing pain, swelling, and loss of function) that cannot be controlled by certain other medications
  2. the effects of methotrexate.2 However, leucovorin calcium, a derivative of tetrahydrofolic acid, may block the effects of methotrexate if given shortly after the methotrexate since it does not require DHFR for activation.2 Moderate (> 100 mg/m2) to high-dose methotrexate (> 1000 mg/m2)4 plus leucovorin rescue is routinely used therapeutically i
  3. Methotrexate can be given by mouth or by injection (intramuscular, intravenous, subcutaneous, or intrathecal). Doses are usually taken weekly, not daily, to limit toxicity. Routine monitoring of the complete blood count, liver function tests, and creatinine are recommended. Measurements of creatinine are recommended at least every two months
  4. To treat arthritis, methotrexate is taken once a week. It is available in oral tablet form (2.5 mg tablets) and in liquid injectable form (25 mg/mL vials or pre-filled syringes) for subcutaneous (under the skin) injection.. The standard dose for tablets ranges from 3 per week (7.5 mg) to 10 per week (25 mg)

Methotrexate: Indication, Dosage, Side Effect, Precaution

  1. Methotrexate is taken as a single ONCE A WEEK dose on the same day each week. It can be taken in two different ways - either by tablets or by injection. Injections are often the preferred way to take the drug because there is evidence that taking methotrexate by injection is more effective and may cause fewer side effects than tablets when treating Crohn's Disease
  2. the inability to have an erection. enlarged breasts. a problem with menstrual periods. acne. joint pain. muscle pain. drowsiness. aphasia, a loss of the ability to speak and understand language
  3. imizes the number of injections and surveillance visits, compared with the multiple dose regimen, and methotrexate is ad
A phase I trial to evaluate the safety and

I took methotrexate for 8 years and always missed a dose when i had a heavy cold. Sometimes my joints would be a bit more nippy the following week but not always. I suffered from really bad headaches too. My Consultant told me to drink my daily allowance of water to the max and keep taking. my folic acid every day except med days inflammatory conditions it is given in smaller doses, once a week. These doses help to control inflammation while avoiding many of the side effects seen with larger doses. How should my child take methotrexate? Methotrexate can be given as an injection under the skin (sub-cutaneous) or by mouth (as small tablets or a liquid) A list of drugs that interact with Methotrexate. Measles, mumps and rubella vaccine, live is predicted to increase the risk of generalised infection (possibly life-threatening) when given with methotrexate (high-dose) These complications and side effects of high-dose methotrexate can be either prevented or decreased by using leucovorin, which provides a source of folic acid for the body's cells. Leucovorin is normally started 24 hours after high-dose methotrexate is given. This delay gives the methotrexate a chance to exert its anti-cancer effects

Methotrexate - Alberta Rheumatolog

Methotrexate should be taken once a week in autoimmune conditions and, less commonly, in some cancer therapy regimens. A European review highlighted continued reports of inadvertent overdose due to more frequent dosing (including daily administration), which has resulted in some fatalities. Subsequently, new measures have been implemented by. Methotrexate has been reported to cause impairment of fertility, oligospermia and menstrual dysfunction in humans, during and for a short period after cessation of therapy. Methotrexate can cause fetal death, embryotoxicity, abortion, or teratogenic effects when administered to a pregnant woman

Methotrexate in Ectopic PregnancyPrescribing IIMethotrexate in ectopic pregnancy prof

Injectable methotrexate is usually supplied in a vial with clear yellow liquid as 50mg in 2ml. Usually five vials are provided on each prescription. It is also available as prefilled syringes (Trexject or Methoblastin PFS) with set doses of 7.5mg, 10mg, 15mg, 20mg and 25mg Methotrexate should not be taken alongside NSAIDs. Fact Methotrexate has been used safely and effectively for RA since its introduction in the 1950s. Myth Methotrexate is toxic. Fact Methotrexate injections can be safely self-administered. Myth Self-administration of methotrexate injections is unsafe Information on Methotrexate Methotrexate is a slow acting drug, which reduces disease activity. It may take up to 3 months, during which time the dose may need to be adjusted, to have its full effect. It can be given by mouth or injection and is usually given once a week. It is important to take methotrexate on the same day each week

Low-Dose Methotrexate: A Mainstay in the Treatment of

chewed. Methotrexate may also be given once a week by injection - either subcutaneous (an injection under the skin), or intramuscular (an injection into a muscle, for example into the buttocks or thigh). If methotrexate is not taken on the normal day, it can be taken within 48 hours Methotrexate 1. Therapeutic Guidelines :Peak serum concentrations of IVIG are achieved immediately following the interavenous injection and is dose related. 30% of the dose is eliminated by catabolism within 24 hr. Serum half life is 3-5 weeks. All batches of IVIG should undergo testing for HIV, syphilis, hepatitis B, and hepatitis

8. Lucas CJ, Dimmit SB, Martin JH. Optimizing low-dose methotrexate for rheumatoid arthritis - A review. Br J Clin Pharmacol 2019;85:2228-34. 9. Mazaud C, Fardet L. Relative risk of and determinants for adverse events of methotrexate prescribed at low dose: a systematic review and meta-analysis of randomized placebo-controlled trials Dose is administered ONCE WEEKLY. Give with or soon after food. IM injection Preferred route for treatment of ectopic pregnancy. Inject into buttock or lateral thigh. Injection is yellow. Intraectopic injection By senior medical staff only. ADULT Medication Monograph METHOTREXATE This document should be read in conjunction with this DISCLAIME What is methotrexate? It is a medicine that can be used to treat an ectopic pregnancy. It stops cells from dividing by interfering with the folic acid in your body. It is given by injection. You often only need 1 dose. Sometimes you will need a second dose. You will need to have blood tests to check the level of pregnancy hormone (hCG) Participants in the two-dose protocol group received intramuscular methotrexate twice at dose of 50 mg/m2 on day 0 and 4. A third dose of methotrexate was given on day 7 if β-hCG levels did not fall 15% between day 4 and 7 after two-dosing. A fourth dose was administered on day 11 if β-hCG levels fell <15% between day 7 and 11 m 2. Methotrexate dose. mg. Methotrexate dose calculated as 50 mg per m 2 (rounded to nearest 0.1 mg), based on DuBois formula for body surface area: 0.007184 x W 0.425 x H 0.725

Methotrexate: Weekly Dosage Explaine

200mg. 350mg. 500mg. injectable solution. 10mg/mL. Methotrexate Overdose. Administer as soon as possible and within 24 hr methotrexate level is >10 -6 M or 48 hour level is >9 x 10 -7 M, the dose of leucovorin should be increased to 100 mg/m 2 IV every 3 hours until methotrexate level is <10 -8 M. Dosing considerations Méthotrexate haute dose > 500 mg/m2. Le méthotrexate (acide 4-amino-10-méthylfolique) est un antagoniste de l' acide folique qui inhibe la réduction de l' acide folique et la prolifération des cellules tissulaires par inhibition de la synthèse des bases puriques et pyrimidiques methotrexate dose. If your child continues to be stable over a period of time on less frequent or smaller methotrexate doses, it will then be stopped. Differences between tablets and injections The amount of methotrexate absorbed when given by mouth depends on the amount of food in the stomach and the dose of methotrexate in the tablet


Methotrexate: Uses, Dosage, Side Effects, Warnings - Drugs

Background/Purpose: Recent recommendations have suggested higher starting doses of methotrexate, i.e. 15 mg/week (3E initiative) in rheumatoid arthritis. However, studies comparing conventional (7.5mg) and newer (15mg) starting dose are limited. Unclear if any difference in control of disease activity or adverse effects with these starting doses. Methods: This randomized controlled trial. Les doses uniques normales se situent dans l'intervalle de 20 à 40 mg/m² de méthotrexate. La dose d'entretien pour la LLA est de 15 à 30 mg/m² une ou deux fois par semaine. Autres exemples : · 3,3 mg/m² en association à d'autres agents cytostatiques une fois par jour pendant 4 à 6 semaines In conclusion, day-1 β-hCG should be used as a predictor for methotrexate treatment success, both in the first and the second injection of methotrexate. Second-dose methotrexate can be given with high reassurance for treatment success to women with a day-1 β-hCG level below 2,234 mIU/mL Low-dose methotrexate (taken once a week) Methotrexate is also used as an intra-muscular injection to terminate ectopic pregnancy, as an alternative to surgery. Use and cost Methotrexate formulations with preservatives must not be used for high-dose treatment or injected into the spine (intrathecal). Methotrexate has caused birth defects and death in unborn babies

Methotrexate and the COVID-19 Vaccine: Should You Stop

* 1 mL syringe with 0.2 mL solution for injection, equivalent to 10 mg methotrexate * 1 mL syringe with 0.25 mL solution for injection, equivalent to 12.5 mg methotrexate * 1 mL syringe with 0.3 mL solution for injection, equivalent to 15 mg methotrexate * 1 mL syringe with 0.35 mL solution for injection, equivalent to 17.5 mg methotrexate Injection: Single-dose pre-filled syringe (in a needle safety device) delivering methotrexate in the following dosage strengths: 7.5mg, 10 mg, 12.5 mg, 15 mg, 17.5 mg, 20 mg, 22.5 mg and 25 mg Methotrexate formulations with preservatives must not be used for high-dose treatment or injected into the spine (intrathecal). Methotrexate has caused birth defects and death in unborn babies. Women must avoid becoming pregnant while using this medication. Pregnant women who have psoriasis or rheumatoid arthritis must not use methotrexate. Pain commonly develops 2 to 7 days after administration of Methotrexate and usually Notify your doctor immediately if severe pain, hypotensive symptoms (dizziness, fainting), or heavy bleeding. Return for follow-up visits as instructed by your doctor. A second dose of Methotrexate is required in approximately 15-20% of patients

Single-dose methotrexate for treatment of ectopic pregnanc

The initial beta-hCG level is the only factor that has significant meaning as predictor of success of repeated injections of methotrexate in the single-dose regimen. Repeated injections of methotrexate may be particularly effective when the initial beta-hCG level is below 6,000 IU/mL Injection: Single-dose auto-injector delivering 0.4 mL of methotrexate in the following dosage strengths: 10 mg, 12.5 mg, 15 mg, 17.5 mg, 20mg, 22.5 mg and 25 mg (3) Methotrexate (MTX) was introduced in 1947 and was initially used to treat leukaemia and other forms of cancer. From the 1980s, methotrexate was used to treat adults with RA, but in very much lower doses (than doses used for leukaemia and cancer) after clinical trials had demonstrated its benefits in RA. Although this article is for people with.

Methotrexate (Injection Route, Subcutaneous Route) Side

Objective The objective of this study was to review our experience with single dose intramuscular methotrexate (MTX) for the treatment of ectopic pregnancy and to evaluate major confounding factors that relate to the success of therapy. Patients and methods The selection criteria were patients who had a stable hemodynamic status and an ectopic gestational mass of <4 cm. on ultrasound. Patients. professionals with expertise in the use of methotrexate. Patients must be trained in proper injection technique for self-administration and explicitly informed about the fact of administration once weekly. The first injection should be performed under direct medical supervision. Dosage errors in the use of methotrexate can result i Methotrexate is available as: a subcutaneous injection (just under the skin) via a pre-filled pen device; a liquid; or tablets. Many patients and parents prefer the injection, which can be associated with fewer side effects. Methotrexate is prescribed as a ONCE weekly dose. It is recommended to take methotrexate on the same day each week

Otrexup or Rasuvo (methotrexate) Injection: 1. Diagnosis of severe, active rheumatoid arthritis, polyarticular juvenile idiopathic arthritis or severe, recalcitrant, disabling psoriasis, AND. 2. Failure or clinically significant adverse effects to generic methotrexate injection, OR medical justification why generic cannot be considered (e.g. Methotrexate is an immunosuppressant drug. It helps to alleviate the symptoms of PsA and slow the progression of the disease. Methotrexate is generally safe when taken at doses required to treat. In order to prevent precipitation of methotrexate in the renal tubules, the patients should maintain an adequate urine flow by drinking plenty of fluids for 2 days after a high dose injection (greater than 200 mg), and keep the urine alkaline by using sodium bicarbonate continuously for at least 24 hours afterwards