phenytoin
noun
phe·nyt·o·in
fə-ˈni-tə-wən 
: a crystalline anticonvulsant compound C15H12N2O2 used in the form of its sodium salt in the treatment of epilepsy
called also diphenylhydantoin
Examples of phenytoin in a Sentence
Recent Examples on the Web
Following 21 days of glutamatergic neural differentiation, three anti-seizure medications – phenytoin, perampanel and carbamazepine – were tested on the SBI epilepsy model.
—
New Atlas, 26 June 2025
There are the anti-seizure medications carbamazepine, lamotrigine and phenytoin and the anti-malarial medications chloroquine and amodiaquine.
—Bruce Y. Lee, Forbes.com, 15 May 2025
Dilantin Dilantin, a common brand of phenytoin, is a prescription drug used to prevent certain types of seizures.
—Karen Berger, Pharmd, Verywell Health, 20 Feb. 2025
Antiepileptic drugs, such as Tegretol (carbamazepine) or Dilantin (phenytoin)
This may not be a complete list of drug interactions.
—Ayesha Gulzar, Verywell Health, 4 Feb. 2025
Examples include lithium, Dilantin (phenytoin), and Cordarone (amiodarone).
—Ruth Jessen Hickman, Md, Health, 23 Dec. 2024
Fortunately, most phenytoin skin rashes are not serious.8 Most phenytoin skin rashes start in the first eight weeks of treatment or when the dose is increased too quickly.
—Sarah Jividen, Verywell Health, 12 Sep. 2024
These medications include certain seizure medications like carbamazepine and phenytoin, barbiturates such as phenobarbital, HIV medications like efavirenz and fosamprenavir, and herbal preparations that contain St. John’s wort.
—Katia Hetter, CNN, 5 Mar. 2024
Epilepsy typically is treated with anti-epileptic drugs (AEDs) such as Topamax (topiramate), Tegretol (carbamazepine), Lamictal (lamotrigine), or Dilantin (phenytoin).
—Diana Apetauerova, Verywell Health, 24 July 2023
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New Atlas, 26 June 2025
There are the anti-seizure medications carbamazepine, lamotrigine and phenytoin and the anti-malarial medications chloroquine and amodiaquine.
—Bruce Y. Lee, Forbes.com, 15 May 2025
Dilantin Dilantin, a common brand of phenytoin, is a prescription drug used to prevent certain types of seizures.
—Karen Berger, Pharmd, Verywell Health, 20 Feb. 2025
Antiepileptic drugs, such as Tegretol (carbamazepine) or Dilantin (phenytoin)
This may not be a complete list of drug interactions.
—Ayesha Gulzar, Verywell Health, 4 Feb. 2025
Examples include lithium, Dilantin (phenytoin), and Cordarone (amiodarone).
—Ruth Jessen Hickman, Md, Health, 23 Dec. 2024
Fortunately, most phenytoin skin rashes are not serious.8 Most phenytoin skin rashes start in the first eight weeks of treatment or when the dose is increased too quickly.
—Sarah Jividen, Verywell Health, 12 Sep. 2024
These medications include certain seizure medications like carbamazepine and phenytoin, barbiturates such as phenobarbital, HIV medications like efavirenz and fosamprenavir, and herbal preparations that contain St. John’s wort.
—Katia Hetter, CNN, 5 Mar. 2024
Epilepsy typically is treated with anti-epileptic drugs (AEDs) such as Topamax (topiramate), Tegretol (carbamazepine), Lamictal (lamotrigine), or Dilantin (phenytoin).
—Diana Apetauerova, Verywell Health, 24 July 2023
Cite this Entry
“Phenytoin.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/phenytoin. Accessed 15 Jul. 2025.
Copy CitationMedical Definition
phenytoin
noun
phe·nyt·o·in
fə-ˈnit-ə-wən
: an anticonvulsant used often in the form of its sodium salt C15H11N2NaO2 to prevent or treat seizures
called also diphenylhydantoin
see dilantinLove words? Need even more definitions?
Merriam-Webster unabridged
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