Comparative Pharmacology
Head-to-head clinical analysis: LYRICA CR versus PHENYTOIN SODIUM.
Peer-Reviewed Evidence
Head-to-head clinical analysis: LYRICA CR versus PHENYTOIN SODIUM.
LYRICA CR vs PHENYTOIN SODIUM
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Binds to the alpha-2-delta subunit of voltage-gated calcium channels in the central nervous system, reducing calcium influx and inhibiting excitatory neurotransmitter release (e.g., glutamate, norepinephrine, substance P).
Stabilizes neuronal membranes and decreases seizure activity by increasing efflux or decreasing influx of sodium ions across cell membranes in the motor cortex during generation of nerve impulses. Prolongs inactivation of voltage-gated sodium channels, reducing repetitive firing of action potentials.
Initial 75 mg orally twice daily (150 mg/day), or 50 mg three times daily (150 mg/day). Based on efficacy and tolerability, may increase to 150 mg twice daily (300 mg/day) after 1 week, then to 225 mg twice daily (450 mg/day) if needed. Maximum dose 450 mg/day. Take with food. Administer whole; do not split, crush, or chew.
Loading dose: 15-20 mg/kg IV (not to exceed 50 mg/min) or oral (1000-1500 mg total in divided doses). Maintenance: 300-400 mg/day PO in 1-2 divided doses or IV (100 mg every 6-8 hours).
None Documented
None Documented
6.3 hours (mean terminal elimination half-life); correlates with creatinine clearance, prolonged in renal impairment.
Mean terminal half-life 22 ± 9 hours (range 7–42 hours), dose-dependent and saturable due to Michaelis-Menten kinetics; half-life increases with higher serum concentrations. Steady state achieved after 7–10 days.
Primarily renal excretion as unchanged drug (98-99% of absorbed dose); <0.1% biliary/fecal.
Primarily hepatic metabolism (CYP2C9, CYP2C19); <5% excreted unchanged in urine. Metabolites (majority p-HPPA) are excreted renally as glucuronide conjugates. Fecal elimination negligible (<2%).
Category C
Category D/X
Anticonvulsant
Anticonvulsant