Monitor serum levels when switching between sodium salt of phenytoin (caps) and free acid form (suspension, Infatabs). Underlying cardiac disease. Use proper dental hygiene. Hormonal contraception. Phenytoin Sodium is the sodium salt form of phenytoin, a hydantoin derivate and non-sedative antiepileptic agent with anticonvulsant activity. Phenytoin sodium promotes sodium efflux from neurons located in the motor cortex, thereby stabilizing the neuron and inhibiting synaptic transmission. Phenytoin is used to control seizures (convulsions) in the treatment of epilepsy. It is also used to prevent and treat seizures that occur during brain surgery. This medicine is an anticonvulsant that works in the brain tissue to stop seizures. CLASSIFICATION AND DRUGS CATEGORY INSTITUTION List of Vital Essential and Necessary Drugs and Medical Sundries for Public Health Institutions SECTION 1 What other drugs will affect phenytoin? Sometimes it is not safe to use certain medications at the same time. Some drugs can affect your blood levels of other drugs you take, which may increase side effects or make the medications less effective. pharmacological classification of drugs. first edition prepared by tariq ahmad department of pharmacy university of lahore. 732. tariq ahmad. pharmacological classification of drugs first edition 732 tariq ahmad | tareeqahmad@hotmail.com department of pharmacy, university of lahore 2. special thanx for support & help to dr aqeel ahmad department of pharmacy university of lahore dr shafiq. Phenytoin, formerly known as diphenylhydantoin, is perhaps the most commonly used major anticonvulsant agent, and is a rare but well known cause of acute idiosyncratic drug induced liver disease that can be severe and even fatal. Phenytoin can cause the platelet or white blood cell counts to drop, increasing the risk of bleeding or infection, respectively. Phenytoin also can cause anemia. Because it interferes with vitamin D metabolism , phenytoin can cause weakening of the bones ( osteomalacia ). Phenytoin (PHT), sold under the brand name Dilantin among others, is an anti-seizure medication. It is useful for the prevention of tonic-clonic seizures and focal seizures , but not absence seizures. [2].