Comparative Pharmacology
Head-to-head clinical analysis: CAPECITABINE versus PURIXAN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: CAPECITABINE versus PURIXAN.
CAPECITABINE vs PURIXAN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Capecitabine is a prodrug that is enzymatically converted to 5-fluorouracil (5-FU) in the body, which inhibits thymidylate synthase and incorporates into RNA and DNA, leading to cytotoxic effects.
Purixan (mercaptopurine) is a purine analog that inhibits de novo purine synthesis by interfering with nucleotide interconversion and incorporation into DNA and RNA. It requires intracellular activation to 6-mercaptopurine ribonucleotide (6-MP ribonucleotide) via hypoxanthine-guanine phosphoribosyltransferase (HGPRT).
Oral, 1250 mg/m2 twice daily for 2 weeks followed by a 1-week rest period.
75 mg/kg once weekly orally; may be increased by 25 mg/kg every 2-4 weeks to a maximum of 150 mg/kg once weekly.
None Documented
None Documented
Clinical Note
moderateCapecitabine + Digoxin
"Capecitabine may decrease the cardiotoxic activities of Digoxin."
Clinical Note
moderateCapecitabine + Digitoxin
"Capecitabine may decrease the cardiotoxic activities of Digitoxin."
Clinical Note
moderateCapecitabine + Deslanoside
"Capecitabine may decrease the cardiotoxic activities of Deslanoside."
Clinical Note
moderateCapecitabine + Acetyldigitoxin
"Capecitabine may decrease the cardiotoxic activities of Acetyldigitoxin."
The terminal elimination half-life of capecitabine is approximately 0.75 hours. For its active metabolite 5-fluorouracil, the half-life is about 0.7 hours. Clinically, this short half-life necessitates twice-daily dosing to maintain therapeutic levels.
Terminal elimination half-life is approximately 3-4 hours in adults with normal renal function; prolonged to 20-50 hours in renal impairment. Clinically, monitoring for myelosuppression is essential due to accumulation.
Capecitabine is predominantly eliminated renally. Approximately 95.5% of the administered dose is recovered in urine, with 61% as unchanged capecitabine and its metabolites. Fecal excretion accounts for about 2.6%. Biliary elimination is minimal (<1%).
Renal excretion of unchanged drug and metabolites; approximately 50% as unchanged drug, 20% as 6-thiouric acid, and minor amounts as other metabolites. Biliary/fecal elimination accounts for less than 10%.
Category D/X
Category C
Antimetabolite
Antimetabolite