Comparative Pharmacology
Head-to-head clinical analysis: PEMETREXED FOR INJECTION versus PEMFEXY.
Peer-Reviewed Evidence
Head-to-head clinical analysis: PEMETREXED FOR INJECTION versus PEMFEXY.
PEMETREXED FOR INJECTION vs PEMFEXY
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Pemetrexed is a folate analog metabolic inhibitor that inhibits thymidylate synthase (TS), dihydrofolate reductase (DHFR), and glycinamide ribonucleotide formyltransferase (GARFT), enzymes involved in folate-dependent de novo synthesis of thymidine and purine nucleotides, thereby disrupting DNA and RNA synthesis.
Pemetrexed inhibits thymidylate synthase (TS), dihydrofolate reductase (DHFR), and glycinamide ribonucleotide formyltransferase (GARFT), which are folate-dependent enzymes involved in nucleotide synthesis, leading to disruption of DNA and RNA synthesis.
500 mg/m² IV over 10 minutes on Day 1 of each 21-day cycle, in combination with cisplatin 75 mg/m² IV over 2 hours starting 30 minutes after pemetrexed completion. Administer folic acid 350-1000 µg po daily starting 7 days before first dose and continuing until 21 days after last dose, vitamin B12 1000 µg IM 7 days before first dose and every 3 cycles thereafter, and dexamethasone 4 mg po twice daily on day before, day of, and day after pemetrexed.
500 mg/m2 intravenously over 10 minutes on day 1 of a 21-day cycle, in combination with cisplatin.
None Documented
None Documented
The terminal elimination half-life is approximately 3-4 hours in patients with normal renal function (creatinine clearance ≥90 mL/min). In patients with impaired renal function (creatinine clearance 45-79 mL/min), the half-life may be prolonged to 4-5 hours.
Terminal elimination half-life ~17 hours (range 13-26 hours) in patients with normal renal function; prolonged to >24 hours in renal impairment. Supports every-21-day dosing.
Approximately 70-90% of the administered dose is excreted unchanged in the urine within 24 hours. Renal elimination is the primary route, with negligible biliary or fecal excretion (<5%).
Renal excretion (70-90% unchanged drug), biliary/fecal (<5%)
Category C
Category C
Antineoplastic Antifolate
Antineoplastic Antifolate