Phenytoin is used to treat certain types of seizures. Common side effects include drowsiness, confusion, slurred speech, trouble with balance or coordination, and uncontrollable eye movements. Phenytoin helps treat symptoms of epilepsy by preventing and regulating seizures. It works by calming overactive nerves in your body. Therapeutic drug monitoring of phenytoin is carried out to ensure effective and safe levels. Some of the factors complicating phenytoin dosing include a narrow therapeutic window, high degree of protein binding, and non-linear pharmacokinetics. However, serum drug levels should only be taken when there is a clear indication to guide patient management. Scenarios where monitoring levels may be. Phenytoin is used to control certain type of seizures, and to treat and prevent seizures that may begin during or after surgery to the brain or nervous system. Phenytoin is in a class of medications called anticonvulsants. Phenytoin, sold under the brand name Dilantin among others, [1] is an anti-seizure medication. [3] It is useful for the prevention of tonic–clonic seizures (also known as grand mal seizures) and focal seizures, but not absence seizures. [3] Phenytoin is used to prevent and control seizures (also called an anticonvulsant or antiepileptic drug). It works by reducing the spread of seizure activity in the brain. Learn about side effects, dosages, drug interactions, and more. Dilantin (phenytoin) is an anti-epileptic drug used to control seizures. Includes Dilantin side effects, interactions and indications. Phenytoin oral capsule is used to treat tonic-clonic and complex partial seizures in people with epilepsy. It can be used alone or in combination with other anti-seizure or antiepileptic drugs. Phenytoin is used to control seizures (convulsions), including tonic-clonic (grand mal) and psychomotor (temporal lobe) seizures, in the treatment of epilepsy. It is also used to prevent and treat seizures that occur during brain surgery. Phenytoin is an anti-epileptic drug, also called an anticonvulsant. Phenytoin works by slowing down impulses in the brain that cause seizures. Phenytoin is used to control seizures. It does not treat all types of seizures, and your doctor will determine if it is the right medicine for you.