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 Antiepileptic drugs should be withdrawn over 2 -3 months at least, and 6 months in the case of benzodiazepines.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.
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.