Antiseizure Drugs Key Points

Mechanism of Action and Contraindications

• Hydantoins (e.g., phenytoin) treat seizures by stabilizing neuronal membranes and reducing excessive neuronal activity.
• Phenytoin should not be used during pregnancy due to potential risks to the fetus.

Therapeutic Ranges and Interactions

• The therapeutic serum range for phenobarbital is 15-40 μg/mL.
• Ethosuximide is used to treat absence seizures by decreasing calcium influx through T-type calcium channels.
• A potentially toxic interaction can occur when taking carbamazepine with other medications.

Antiseizure Drugs and Safety

• The safety and efficacy of felbamate have not been established for children younger than 2 years of age.
• Pregnant individuals taking antiseizure drugs have a higher risk of birth defects.

Epilepsy and Seizures

• The incidence of epilepsy developing in children who have had one or more febrile seizures is 2-7%.
• Status epilepticus is considered a life-threatening emergency that requires immediate medical attention.
• Pharmacologic agents of choice for treating status epilepticus include benzodiazepines, phenytoin, and barbiturates.

Antiseizure Drugs and Hemorrhage

• Antiseizure drugs can act as inhibitors of vitamin K, contributing to hemorrhage in infants shortly after birth.
• Pregnant individuals should take vitamin K supplements daily to prevent increased bleeding.

Characteristics of Seizure Disorders

• The main characteristic of seizure disorders is recurrent seizures due to abnormal electrical activity in the brain.
• Imaging techniques such as EEG, CT, and MRI are useful in diagnosing epilepsy.
• 70% of seizure cases are considered primary or idiopathic.

Types of Seizures

• Tonic-clonic seizures were formerly known as grand mal seizures.
• Absence seizures were formerly known as petit mal seizures.
• Antiseizure drugs increase the threshold for nerve cell membrane excitability.

Age and Seizures

• The majority of people with epilepsy experience their first seizure between the ages of 10 and 20.

Role of Antiseizure Drugs

• The main role of antiseizure drugs is to reduce the frequency and severity of seizures.

Causes of Seizures

• The main cause of secondary seizure cases is head trauma.
• Epilepsy is a type of disorder that can lead to recurrent seizures.
• Infections, such as meningitis, could result in seizures but are not associated with epilepsy.