Antiepileptic Drugs (AEDs)

 Anticonvulsants are drugs used to treat seizure disorders; varying in mechanisms of action and can work multiple mechanisms at once.

AEDs affect the influx of sodium, calcium, or chloride ions across the nerve cell membrane in some way; slowing the transmission of erratic nerve impulses because membranes are less excitable.

Glutamate is an excitatory neurotransmitter affecting sodium and calcium influx; GABA is an inhibitory neurotransmitter affecting chloride influx. Some anticonvulsants work directly on ion channels, where others inhibit glutamate or enhance GABA; some work multiple ways.

Drug therapy is individualized for the patient; beginning with monotherapy, adding other agents to control seizure activity.

Status epilepticus treatment, in an emergency, includes one of two benzodiazepines (diazepam (Valium) or Lorazepam (Ativan)) plus phenytoin (Dilantin) or fosphenytoin (Cerebyx).

Some AEDs have other uses; gabapentin (Neurontin) is frequently used to treat nerve pain related to diabetic neuropathy, nerve injury, and shingles. AED side effects are dose-dependent, and dosing is highly individualized. Many AEDs cause drowsiness, dizziness, and mental confusion; patients should be cautioned to be careful when driving or making important decisions; auxiliary labels should warn of this and sedation.

Patients should avoid drinking alcohol while taking these drugs. Severe side effects include Stevens-Johnson syndrome and blood abnormalities.

• AEDs should not be stopped abruptly because discontinuation may cause seizures; the dose should instead be slowly decreased over time.

  
  

  Anticonvulsants are classified pregnancy category D.
• • There is positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience or studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.
• There are many interactions between anticonvulsants and other drugs.
  
  
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