Comparative Pharmacology
Head-to-head clinical analysis: MERCAPTOPURINE versus OTREXUP PFS.
Peer-Reviewed Evidence
Head-to-head clinical analysis: MERCAPTOPURINE versus OTREXUP PFS.
MERCAPTOPURINE vs OTREXUP PFS
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Mercaptopurine is a prodrug that is converted to 6-thioguanine nucleotides, which inhibit de novo purine synthesis and DNA replication by incorporating into DNA and RNA. It also inhibits purine nucleotide interconversions via feedback inhibition of amidophosphoribosyltransferase.
Methotrexate is a folate analog that inhibits dihydrofolate reductase, thereby blocking the synthesis of purines and pyrimidines, leading to inhibition of DNA synthesis and cell proliferation. It also has immunosuppressive and anti-inflammatory effects through modulation of adenosine pathways and cytokine release.
1.5 to 2.5 mg/kg orally once daily; maintenance 1.5 to 2.5 mg/kg orally once daily.
Methotrexate 7.5-15 mg subcutaneously once weekly. For rheumatoid arthritis, start at 7.5 mg weekly, titrate to 20-25 mg weekly as tolerated.
None Documented
None Documented
Clinical Note
moderateMercaptopurine + Digoxin
"Mercaptopurine may decrease the cardiotoxic activities of Digoxin."
Clinical Note
moderateMercaptopurine + Digitoxin
"Mercaptopurine may decrease the cardiotoxic activities of Digitoxin."
Clinical Note
moderateMercaptopurine + Deslanoside
"Mercaptopurine may decrease the cardiotoxic activities of Deslanoside."
Clinical Note
moderateMercaptopurine + Acetyldigitoxin
"Mercaptopurine may decrease the cardiotoxic activities of Acetyldigitoxin."
Terminal elimination half-life: 1.5-3 hours (variable); for active metabolites (e.g., 6-thioguanine nucleotides) half-life is 5-7 days, which correlates with myelosuppression.
5-8 hours (low-dose methotrexate); 8-15 hours (high-dose). Prolonged in renal impairment, third-space effusions, or concomitant NSAIDs.
Renal: 20-30% as unchanged drug; biliary/fecal: minor; extensive hepatic metabolism to active and inactive metabolites.
Renal excretion (80-90% unchanged) via glomerular filtration and tubular secretion; biliary/fecal elimination accounts for <10%.
Category D/X
Category C
Antimetabolite
Antimetabolite