Comparison of acute, chronic and post-treatment effects of carbamazepine and vinpocetine on hearing loss and seizures induced by 4-aminopyridine.
OBJECTIVE
To compare the acute, chronic and post-treatment effects of the classic antiepileptic drug carbamazepine (CBZ) and the potential antiepileptic vinpocetine (VPC), successfully used in the treatment of brain vascular origin disorders, on 4-aminopyridine (4-AP)-induced increase in auditory threshold, brain-auditory-evoked-potentials (BAEPs) later waves alterations and epileptiform activity.


METHODS
BAEP and EEG recordings before and following 4-AP (3mg/kg, i.p.) were obtained in guinea pigs. One week after, the animals received a daily injection (i.p.) of vehicle, 3mg/kg VPC or 17 mg/kg CBZ for 13 days. The acute and chronic effects before and following 4-AP were tested at the 1st and last days, respectively, and the post-treatment effect 1 month after the end of treatment.


RESULTS
CBZ and 4-AP increased BAEPs threshold and BAEPs P4 wave latency. Chronic CBZ inhibited 4-AP-induced increase in P3 amplitude. In the VPC-treated group, all the 4-AP-induced BAEPs changes were prevented. Seizures were prevented in 50% and 75% of the animals by chronic CBZ and VPC, respectively. After acute VPC and after the end of VPC-treatment 4-AP failed to induce seizures in 50% of the animals.


CONCLUSIONS
VPC inhibits 4-AP-induced seizures and hearing loss, even after post-treatment, at a concentration about 10 times lower than CBZ.


CONCLUSIONS
The complications in hearing that can accompany epilepsy can be prevented by VPC, indicating its advantage as an alternative antiepileptic.
Nekrassov
Vladimir
V
Instituto Nacional de Rehabilitación, SSA, Mexico.
Sitges
María
M
D015761:4-Aminopyridine; D000161:Acoustic Stimulation / Q000379:methods; D000818:Animals; D000927:Anticonvulsants / Q000627:therapeutic use*; D001309:Auditory Threshold / Q000187:drug effects; D002220:Carbamazepine / Q000627:therapeutic use*; D004195:Disease Models, Animal; D004347:Drug Interactions; D005072:Evoked Potentials, Auditory / Q000187:drug effects; D006168:Guinea Pigs; D034381:Hearing Loss / Q000139:chemically induced / Q000188:drug therapy*; D008297:Male; D011571:Psychoacoustics; D012640:Seizures / Q000139:chemically induced / Q000188:drug therapy*; D013997:Time Factors; D014748:Vinca Alkaloids / Q000627:therapeutic use*
D000927:Anticonvulsants; D014748:Vinca Alkaloids; D002220:Carbamazepine; C013983:vinpocetine; D015761:4-Aminopyridine