English 
简体中文 Phenytoin Sodium (PHT)
1) The main possible mechanism: voltage-gated sodium channel blocker.
2) Therapeutic indications: mainly suitable for focal epilepsy.
3) Warning: People who have a history of hypersensitivity to hydantoin or who have cardiac dysfunction such as Adams-Stokes syndrome, II-III degree atrioventricular block, sinus node block, sinus bradycardia, etc. should not be used. It is not suitable for epilepsy patients with absence seizures or myoclonic seizures, because these patients may get worse after taking it.
4) Dosage for children: Click to view the dosage for children of different ages and weights.
5) Major adverse reactions in children: Allergic rash (can be accompanied by high fever, severe rashes such as Stevens-Johnson and Lyell syndrome can be life-threatening, but relatively rare) and liver damage. In addition, long-term use of phenytoin is prone to acne, gum hyperplasia, rough face, hairy, osteoporosis, and lack of vitamin K and folic acid. There are also dose-related side effects such as nystagmus, ataxia, anorexia, nausea, vomiting, aggressive behavior, and megaloblastic anemia.
6) Interaction with other anti-epileptic drugs: Because of its hepatic enzymes induction effect, it can reduce the blood concentration of antiepileptic drugs such as valproate, carbamazepine, oxcarbazepine, lamotrigine, clonazepam, perampanel (but often increase the concentration of phenobarbital). In short, the blood drug concentration should be closely monitored after combined use with phenytoin sodium, which is easy to affect others and easy to be influenced by others.
7) Interaction with non-anti-epileptic drugs: 1. Long-term combined use of acetaminophen can increase its liver toxicity and reduce the efficacy. 2. Combined with anticoagulant drugs, the initial anticoagulant effect will be enhanced, but continuous application will weaken. It is necessary to closely monitor the prothrombin time. 3. Drinking alcohol has an effect on the blood concentration of the drug, try to avoid drinking alcohol. 4. Combined use with calcium carbonate can reduce the bioavailability of phenytoin sodium. It should be taken 2-3 hours apart. 5. In principle, patients who use dopamine should not use this drug. 6. When combined with lidocaine or propranolol, it will aggravate the cardiac depressive effect, so be careful. 7. If combined with a large number of antipsychotics or tricyclic antidepressants, it may induce seizures, and the dosage of this drug needs to be adjusted.