This is often a question of clinical choice but the following summary may be of practical use. In the case of a child with infantile spasms the use of adrenocorticotrophic hormone (ACTH) or glucocorticoids would appear to be essential. Similarly ethosuximide has a high degree of specificity for the treatment of generalized absence seizures. However, in the majority of seizure types there is a considerable overlap between the various antiepileptic drugs. Apart from carbamazepine which may be superior to the other drugs for the treatment of complex partial seizures, the choice of drug will largely depend on the tolerance of the patient to the adverse side effects. For example, phenytoin is often unsuitable because of its frequent, and often intolerable, side effects. Teratogenic effects are common with most anticonvulsant drugs although there is some evidence that carbamazepine is less teratogenic than most of these drugs. It should also be emphasized that in pregnancy the metabolism of most anticonvulsants is increased so that the plasma drug concentrations should be monitored if the therapeutic efficacy of the drug is in doubt.
In CONCLUSION, epilepsy is a term used to describe a variety of recurrent symptoms which result from the synchronous or sustained discharge of a group of neurons. It is not clear which specific abnormality in synaptic function is associated with epilepsy, but there is some evidence that an impairment of inhibitory transmission in the neocortex and hippocampus may be primarily involved. The possible causative role of GABA is supported by the fact that many clinically useful anticonvulsants facilitate GABA transmission. Other anticonvulsants may owe their efficacy to their ability to stabilize cation movements across neuronal membranes and/or to affect the phosphorylation of membrane proteins.
With regard to the antiepileptic drugs that are currently available, no attempt has been made to be entirely comprehensive. There are a number of exciting developments in the search for novel anticonvulsants, of which the selective GABA transaminase inhibitor gamma-vinyl GABA (vigabatrin) is particularly interesting. However, we must await the outcome of the extensive clinical trials before a proper assessment may be made of its efficacy and lack of toxicity. Another novel approach to the treatment of epilepsy has been to reduce the functional activity of the glutaminergic pathway in the cortical and limbic regions of the brain. Lamotrigine has recently been introduced for the treatment of partial seizures and generalized tonic-clonic seizures that are not satisfactorily controlled by standard medication. Lamotrigine acts by reducing the excitatory effects of glutamate by acting as an NMDA receptor antagonist. Perhaps the most unique antiepileptic drug to be developed so far is gabapentin, the mechanism of action of which still remains elusive.
Was this article helpful?