Comparative Pharmacology
Head-to-head clinical analysis: MERCAPTOPURINE versus TREXALL.
Peer-Reviewed Evidence
Head-to-head clinical analysis: MERCAPTOPURINE versus TREXALL.
MERCAPTOPURINE vs TREXALL
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, preventing the conversion of folic acid to tetrahydrofolate, thereby inhibiting DNA synthesis, repair, and cellular replication. It also has immunomodulatory and anti-inflammatory effects through inhibition of purine and pyrimidine synthesis and release of adenosine.
1.5 to 2.5 mg/kg orally once daily; maintenance 1.5 to 2.5 mg/kg orally once daily.
Oral: 7.5-15 mg once weekly; subcutaneous: 7.5-15 mg once weekly for rheumatoid arthritis; may be increased up to 25-30 mg weekly based on response and tolerability.
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.
Terminal elimination half-life is 3-10 hours; for high-dose methotrexate, half-life is 8-15 hours. Clinically, monitoring at 24, 48, and 72 hours is standard to guide leucovorin rescue
Renal: 20-30% as unchanged drug; biliary/fecal: minor; extensive hepatic metabolism to active and inactive metabolites.
Renal excretion of unchanged drug accounts for 80-90% of elimination; biliary/fecal elimination is minor (<10%)
Category D/X
Category C
Antimetabolite
Antimetabolite