Comparative Pharmacology
Head-to-head clinical analysis: DILANTIN 125 versus LYRICA CR.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DILANTIN 125 versus LYRICA CR.
DILANTIN-125 vs LYRICA CR
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Phenytoin stabilizes neuronal membranes by promoting voltage-gated sodium channel inactivation, reducing high-frequency neuronal firing and seizure propagation.
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).
300-400 mg per day orally in divided doses (e.g., 100 mg three times daily); loading dose 1 g orally divided into three doses given at 2-hour intervals, then 100 mg every 6-8 hours for first 24 hours.
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.
None Documented
None Documented
Terminal half-life: 7-42 hours (mean 22 hours) in adults; dose-dependent due to saturable metabolism. Steady-state reached in 7-10 days.
6.3 hours (mean terminal elimination half-life); correlates with creatinine clearance, prolonged in renal impairment.
Renal: 70% as metabolites (mainly HPPA glucuronide and sulfate), 5-10% as unchanged drug. Fecal: 30% (minor).
Primarily renal excretion as unchanged drug (98-99% of absorbed dose); <0.1% biliary/fecal.
Category C
Category C
Anticonvulsant
Anticonvulsant