Methotrexate (METHOTREXATE)

Used extensively across all areas of oncology, including both medical oncology and hematology oncology.

Oral: Please refer to specific protocol being used as doses may vary greatly.

Available as 2.5 mg tablets. Tablets contain lactose. Tablets should NOT be crushed or broken. Store at room temperature and protect from light.

Antimetabolite (Antifolate)

Take on an empty stomach, at least 1 hour before or 2 hours after food

Once daily dosing: If a dose is missed, patients should be instructed to take it as soon as they can if it is within 12 hours of the missed dose. If it is over 12 hours since the missed dose, patients should skip the missed dose and resume with the next scheduled dose.

Once or twice weekly dosing: If a dose is missed, patients should be instructed to take it as soon as they can if it is within 24 hours of the missed dose. If it is over 24 hours since the missed dose, patients be instructed to contact their healthcare team for guidance.

Common: Neutropenia, Thrombocytopenia, Stomatitis, Fatigue, Nausea, Vomiting.

Less Common: Hepatotoxicity, Pulmonary toxicity.

The adverse effects listed above are not exhaustive. Please refer to the relevant product monograph for full details.

Baseline before treatment: CBC & differential, platelets, SCr, BUN, AST, ALT, ALP, bilirubin.

During treatment: CBC & differential, platelets, SCr, BUN, AST, ALT, ALP, bilirubin. Frequency dependent on protocol and physician discretion.

• Proton Pump inhibitors may increase the serum concentration of methotrexate.
• Sulfa containing medications may increase serum concentration of methotrexate.
• Penicillin may increase the serum concentration of methotrexate.
• Nonsteroidal Anti-Inflammatory medications (NSAIDs) may increase the serum concentration of methotrexate.
• This drug can impact or be impacted by metabolic enzymes for absorption and excretion. Many drugs can also affect or be affected by these enzymes, so please consult with pharmacy to assess for interactions.
• Current drug interaction databases should be consulted for more information.

• Avoid in pregnancy and lactation.
• Methotrexate elimination is reduced in patients with impaired renal function, ascites, or pleural effusions.
• Methotrexate-induced lung disease is a potentially dangerous lesion, which may occur acutely at any time during therapy, and has been reported at doses as low as 7.5 mg/week. It is not always fully reversible. Pulmonary symptoms (especially a dry, nonproductive cough) may require interruption of treatment and careful investigation.

BC Cancer. BC Cancer Drug Manual. Methotrexate.  Vancouver, British Columbia: BC Cancer Agency. Available at:  http://www.bccancer.bc.ca/drug-database-site/Drug%20Index/Methotrexate_monograph.pdf. Updated July 1, 2023.  Accessed February 2, 2024.

Lexicomp. Methotrexate Monograph. In: Lexi-Drugs. Hudson, Ohio: Lexi-Comp, Inc. Available at: https://online-lexi-com.qe2a-proxy.mun.ca/lco/action/doc/retrieve/docid/patch_f/7270?cesid=137pl1VLuQJ&searchUrl=%2Flco%2Faction%2Fsearch%3Fq%3Dmethotrexate%26t%3Dname%26acs%3Dtrue%26acq%3Dmethotrexate. Updated February 2, 2024. Accessed February 2, 2024.

Cancer Care Ontario. Methotrexate Monograph. Drug Formulary. Toronto, Ontario: Cancer Care Ontario. Available at: https://www.cancercareontario.ca/en/drugformulary/drugs/monograph/44166. Updated November 2022. Accessed January 22, 2024.

Mayne Pharma. Apo-methotrexate Tablet Product Monograph. Montreal, Quebec. Updated December 14, 2017.