Phenytoin is a widely used anticonvulsant medication belonging to the hydantoin class, primarily indicated for the treatment of generalized tonic-clonic seizures, partial seizures, and status epilepticus. It acts by stabilizing neuronal membranes and reducing repetitive firing of action potentials, primarily through modulation of voltage-gated sodium channels. First synthesized in 1908, phenytoin’s anticonvulsant properties were discovered in 1938 by H. H. Merritt and Tracy Putnam, marking a major breakthrough in epilepsy management. Introduced clinically in the 1940s, it became the first widely used non-sedating antiepileptic, offering effective seizure control without the profound sedation associated with barbiturates. Over the decades, phenytoin has remained a mainstay in epilepsy therapy due to its efficacy, long history of clinical use, and cost-effectiveness, although careful monitoring is required to manage its potential side effects and narrow therapeutic window. Its development laid the foundation for modern antiepileptic drug research, influencing the design of newer anticonvulsants.
