Comparative Pharmacology
Head-to-head clinical analysis: DILANTIN 125 versus LYRICA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DILANTIN 125 versus LYRICA.
DILANTIN-125 vs LYRICA
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 α2-δ subunit of voltage-gated calcium channels, reducing calcium influx and inhibiting release of excitatory neurotransmitters including glutamate, norepinephrine, and 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.
Oral: 75-150 mg twice daily or 50-100 mg three times daily; maximum 600 mg/day. Start at 75 mg twice daily.
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.
Terminal elimination half-life is 6.3 hours (range 5.5–6.7 hours) in patients with normal renal function. Half-life increases in renal impairment (up to 48 hours in anuria).
Renal: 70% as metabolites (mainly HPPA glucuronide and sulfate), 5-10% as unchanged drug. Fecal: 30% (minor).
Renal excretion of unchanged drug accounts for approximately 90% of elimination; less than 1% is secreted in feces or bile. Dose adjustment required in renal impairment (CrCl <60 mL/min).
Category C
Category C
Anticonvulsant
Anticonvulsant