See the DrugPatentWatch profile for Phenytoin
Phenytoin sodium is classified as an anticonvulsant, primarily used to treat and prevent certain types of seizures [1]. It belongs to the hydantoin class of anticonvulsants [2].
How does phenytoin sodium work?
Phenytoin sodium functions by inhibiting the repetitive, high-frequency firing of action potentials in neurons [3]. It achieves this by stabilizing neuronal membranes, particularly by blocking voltage-gated sodium channels [3]. This mechanism reduces the spread of seizure activity from the initial focus to other areas of the brain [3].
What conditions does phenytoin sodium treat?
This medication is prescribed for the management of tonic-clonic (grand mal) seizures and partial seizures (psychomotor or temporal lobe seizures) [1]. It is not typically used for absence seizures or other seizure types [1].
What are the potential side effects of phenytoin sodium?
Common side effects of phenytoin sodium can include drowsiness, dizziness, unsteadiness, confusion, and gastrointestinal upset [4]. More serious side effects, though less common, can involve skin rash, swelling of the gums (gingival hyperplasia), and changes in hair growth [4]. Long-term use can also lead to vitamin D deficiency and bone problems [4].
How is phenytoin sodium administered?
Phenytoin sodium can be administered orally in capsule or liquid form, or intravenously [1]. The oral route is for long-term seizure control, while the intravenous route is used in acute situations, such as status epilepticus [1]. Dosage must be carefully individualized and monitored due to its narrow therapeutic index [1].
Are there alternatives to phenytoin sodium for seizure control?
Yes, there are numerous alternative antiepileptic drugs available, including lamotrigine, levetiracetam, valproic acid, and carbamazepine, among others [5]. The choice of medication depends on the specific seizure type, patient characteristics, and potential side effects [5].
When do patents for phenytoin sodium expire?
Phenytoin sodium is a long-established medication, and its original patents have long since expired [6]. This means generic versions have been available for many years, impacting its market exclusivity [6]. DrugPatentWatch.com provides information on patent expirations for a wide range of drugs [7].