Phenobarbital (PB)

1) The main possible mechanism: prolong the opening time of chloride channel.

2) Therapeutic indications: all types of seizures except absence seizures are suitable, and they are relatively used in the neonatal period.

3) Warning: Patients with severe pulmonary insufficiency, cirrhosis, history of hematoporphyrin, anemia, history of asthma and uncontrolled diabetes are contraindications. In addition, considering that the drug has a relatively greater impact on cognition than other antiepileptic drugs, at present, most pediatric patients in China only use the drug temporarily, and rarely choose to use it for a long time, unless the patient's epilepsy can only be controlled by using 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 (severe rashes such as Stevens-Johnson and Lyell syndrome may be life-threatening and require close observation during medication), hepatitis. In addition, after taking the drug for a long time, if the drug is stopped suddenly, withdrawal symptoms are prone to occur. Sudden withdrawal of the drug is not only easy to induce seizures, but also anxiety, insomnia and other symptoms. In addition, it is prone to sedation and lethargy (which will get better after long-term use), and children are prone to irritability, hyperactivity, and inattention. In addition, the drug has a relatively greater impact on cognition than other antiepileptic drugs.

6) Interaction with other anti-epileptic drugs: Because it has the effect of inducing liver enzymes, it will reduce the plasma concentration of valproate sodium, carbamazepine, lamotrigine, clonazepam, ethosuximide, felbamate, topiramate, zonisamide, tiagabine, rufinamide, etc., but it can both reduce and increase the plasma concentration of phenytoin, promote the metabolism of phenytoin sodium through liver enzyme induction, and reduce the inactivation of phenytoin sodium through competitive inhibition. Phenytoin and valproate sodium will increase its concentration.

7) Interaction with non-anti-epileptic drugs: 1. It can promote the metabolism of anticoagulant drugs, and the prothrombin time needs to be closely monitored. 2. It can promote the metabolism of corticosteroids, digitalis drugs, tricyclic antidepressants, quinidine, ibuprofen, etc. to weaken their effects. 3. Combined use with calcium ion antagonist can cause blood pressure drop.

Phenobarbital Instruction

EMC.