الرحمن الله بسمالرحيم

ANTIEPILEPTICS

Dr: Samah Gaafar Hassan

EPILEPSY a periodic recurrence of seizures with or

without convulsions. A convulsion implies violent,

involuntary contraction(s) of the voluntary muscles.

A seizure results from an excessive discharge of cortical neurons and is characterized by changes in electrical activity as measured by the electroencephalogram (EEG).

GOALS OF THERAPY The goal of treatment is to control or

reduce the frequency of seizures and ensure compliance, allowing the patient to live as normal a life as possible. Complete suppression of seizures must be balanced against tolerability of side effects, and the patient should be involved in defining the balance.

The mechanism of action of most AEDs includes effects on ion channels (sodium and calcium), inhibitory neurotransmission (GABA), or excitatory neurotransmission (glutamate and aspartate).

CARBAMAZEPINE Blocks voltage-gated sodium channels. Partial seizures, generalized tonic clonic,

trigeminal neuralgia. An enzyme inducer. (own induction) Has active metabolite carbamazepine-

10,11-epoxide. S.E

Neurosensory side effects (e.g., diplopia, blurred vision, nystagmus, ataxia.

Hyponatremia. Drug interaction valporic acid,

clarithromycin, errythromycin.

ETHOSUXAMIDE inhibits type T- Ca channels. Only for absence seizures.

FELBAMATE: Broad spectrum antiepileptic. glycine receptor antagonist. Aplastic anaemia & hepatitis.

GABAPENTIN second-line agent for patients with

partial seizures. Less side effect & less drug interaction In elderly. Renal excretion. LAMOTRIGINE: Broad spectrum. Drug interaction enzyme indution &

inhibition. Eldery.

PHENOBARBITAL Enhances the GABA effect. Choice in neonatal seizures. In SE. PHENYTOIN: Partial, generalized tonic clonic & SE. 90% binding to plasma protein. Is an enzyme inducer. Zero-order elimination. S.E: ataxia, nystagmus, gengival

hypertrophy. Folic acid deficiency.

VALPORIC ACID Partial & primary generalized. >90% is plasma protein bound. Is an enzyme inhibitor. S.E: hepatotoxicity, pancytopenia, POS,

hair loss, menstrual irregularities.

GENERAL PRINCIPLES 2-5 yrs. Compliance. Barbiturates and phenytoin are

associated with congenital heart malformations and facial clefts. Valproic acid and carbamazepine are associated with spina bifida.

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