TRC: Antiepileptic drugs

Antiepileptic drugs

Antiepileptics

The treatment of epilepsy is aimed at restoring the inhibitory functions in the brain and suppressing seizure activity. Three major mechanisms of drug action are used:

1. Potentiating GABA to enhance the inhibitory control and modulate the abnormal firing by:

Activating GABA-receptors (benzodiazepines and barbiturates; yellow drugs)
Inhibiting GABA reuptake (tiagabine; black drugs)
Inhibiting GABA breakdown (vigabatrin, valproic acid; not shown)

2. Sodium channel inhibitors to prevent repetitive firing of neurons in a potential seizure focus (white drugs: phenytoin, carbamazepine, lamotrigine, valproic acid)

3. Calcium channel inhibitors to control bursting of these channels during absences. (blue drugs: ethosuximide, valproic acid)

When considering stopping antiepileptic drugs the patient should

Extra info: It is recommended to stop driving during withdrawal and then wait until the patient has been seizure free off medication for 6 months before resuming driving. Withdrawing treatment is considered usually after 2-4 years seizure free. Antiepileptic drugs should be withdrawn over 2 -3 months at least, and 6 months in the case of benzodiazepines. Changing diet has no effect.

Option explanation:

stop driving until the drug has been successfully withdrawn

not consider withdrawing treatment unless they have been seizure free for a year

taper antiepileptic drugs over a period of 3 months or so

change diet and add more vitamin B

A patient is brought to the emergency room in status epilepticus. Which of the following is NOT indicated in the management of his condition?

Extra info: Intramuscular phenytoin will only slowly and not fully absorbed from the muscle which is inappropriate for a patient in status.

Option explanation:

administration of oxygen

single dose diazepam 10 mg intravenously

blood glucose determination

begin phenytoin 300 mg intramuscularly