Comparative Pharmacology
Head-to-head clinical analysis: FUSILEV versus VALNAC.
Peer-Reviewed Evidence
Head-to-head clinical analysis: FUSILEV versus VALNAC.
FUSILEV vs VALNAC
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
FUSILEV (levoleucovorin) is the pharmacologically active isomer of folinic acid. It bypasses dihydrofolate reductase inhibition by dihydrofolate reductase inhibitors (e.g., methotrexate), providing reduced folate that is used in DNA synthesis and repair. It also enhances the efficacy of fluorouracil by stabilizing the ternary complex of thymidylate synthase, thereby inhibiting DNA synthesis.
Valproate semisodium (valproic acid derivative) increases GABA levels in the brain by inhibiting GABA transaminase and succinic semialdehyde dehydrogenase, and modulates voltage-gated sodium channels and T-type calcium channels. The combination (valproate semisodium) dissociates in the gastrointestinal tract to valproic acid and sodium valproate, providing rapid absorption and sustained release.
Leucovorin (Fusilev) 200 mg/m2 IV over 2 hours, followed by 5-fluorouracil bolus and infusion, repeated every 2 weeks in combination regimens for advanced colorectal cancer.
Adults: 650 mg orally twice daily, with a maximum of 1300 mg per day.
None Documented
None Documented
The terminal elimination half-life of the active metabolite, 5-methyltetrahydrofolate (5-MTHF), is approximately 6-8 hours in healthy adults; clinically, this supports twice-daily or daily dosing schedules.
3-5 hours (healthy adults). In severe renal impairment (CrCl <30 mL/min), half-life extends to 12-24 hours, increasing risk of accumulation and toxicity.
Primarily hepatic metabolism; renal excretion of metabolites accounts for approximately 40-60% of the dose; fecal excretion is negligible.
Primarily renal (90% unchanged drug), with 10% biliary-fecal. In renal impairment, half-life prolongs significantly, requiring dose adjustment.
Category C
Category C
Antidote
Antidote