DIVALPROEX SODIUM vs PHENYTOIN SODIUM
Independent side-by-side comparison.
Possible drug interaction. DIVALPROEX SODIUM and PHENYTOIN SODIUM are different prescription medicines. Combining or switching between them can cause interactions — talk to a pharmacist or prescriber before making changes. This page is not medical advice.
Rating
68/100
New
Pharmacy pays
~$5.99 /30
$0.18 /mL
Type
RX
RX
Active ingredient
DIVALPROEX SODIUM
PHENYTOIN SODIUM
Manufacturer
Dosage forms
Capsule, Oral pellets, Capsule, delayed release, Tablet, delayed release, Tablet, extended release
Capsule, Injectable
Drug class
Anti-Epileptic Agent
Anti-Epileptic Agent
Boxed warning
None
Half-life
about 9 to 16 hours (the label's mean terminal half-life range for valproate monotherapy)
About 22 hours on average, ranging from 7 to 42 hours — but phenytoin does NOT have a single fixed half-life. It follows nonlinear, saturable (Michaelis-Menten) kinetics, so the half-life lengthens as the dose and blood level rise; the label warns that "small incremental doses may increase the half-life and produce very substantial increases in serum levels" once levels are in the upper range.
Treats
Bipolar Disorder, Epilepsy, Absence Epilepsy
Tonic-Clonic Epilepsy, Temporal Lobe Epilepsy, Status Epilepticus
Frequently asked questions
What is the difference between Divalproex Sodium and Phenytoin Sodium?
Divalproex Sodium contains Divalproex Sodium, while Phenytoin Sodium contains Phenytoin Sodium — they have different active ingredients.
Ratings are based on FDA regulatory (recall-safety) data. This comparison is for general reference only — not medical advice. Always consult a licensed professional before choosing or switching a medication.