Influence of levetiracetam on the anticonvulsant efficacy of conventional antiepileptic drugs against audiogenic seizures in DBA/2 mice.
Levetiracetam (LEV, [S]-alpha-ethyl-2-oxo-1-pyrrolidine acetamide) is a new antiepileptic that has been used as adjunctive therapy to treat patients with intractable epilepsy. Systemic administration of levetiracetam (2.5-30 mg/kg, intraperitoneally (i.p.)) was able to produce a dose-dependent decrease in DBA/2 audiogenic seizure severity score. In combination with conventional antiepileptic drugs, levetiracetam, 5mg/kg, i.p., which per se did not significantly affect the occurrence of audiogenic seizures in DBA/2 mice, potentiated the anticonvulsant activity of some antiepileptic drugs studied against sound-induced seizures in DBA/2 mice. The degree of potentiation induced by levetiracetam was greater, approximately twice, for carbamazepine, diazepam, felbamate, topiramate, gabapentin, and valproate, less for lamotrigine, phenobarbital and phenytoin. This increase was associated with a comparable impairment in motor activity; however, the therapeutic index of combined treatment of antiepileptic drugs with levetiracetam was more favourable than the combination with saline with the exception of lamotrigine, phenytoin and phenobarbital. Since levetiracetam did not significantly influence the total and free plasma and the brain levels of antiepileptics studied. In addition, levetiracetam did not significantly affect the hypothermic effects of the anticonvulsants tested. In conclusion, levetiracetam showed an additive anticonvulsant effect when administered in combination with some classical anticonvulsants, most notably carbamazepine, diazepam, felbamate, gabapentin, topiramate and valproate, implicating a possible therapeutic relevance of such drug combinations.
Donato Di Paola
Eugenio
E
Section of Pharmacology, Department of Experimental and Clinical Medicine, Faculty of Medicine and Surgery, University of Catanzaro, Catanzaro, Italy.
Gareri
Pietro
P
Davoli
Alessandro
A
Gratteri
Santo
S
Scicchitano
Francesca
F
Naccari
Clara
C
De Sarro
Giovambattista
G
D000161:Acoustic Stimulation; D000818:Animals; D000927:Anticonvulsants / Q000493:pharmacokinetics / Q000627:therapeutic use*; D001259:Ataxia / Q000139:chemically induced; D001522:Behavior, Animal / Q000187:drug effects; D001831:Body Temperature / Q000187:drug effects; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D020195:Epilepsy, Reflex / Q000188:drug therapy*; D000077287:Levetiracetam; D051379:Mice; D008811:Mice, Inbred DBA; D009043:Motor Activity / Q000187:drug effects; D010863:Piloerection / Q000187:drug effects; D010889:Piracetam / Q000031:analogs & derivatives* / Q000493:pharmacokinetics / Q000627:therapeutic use; D004856:Postural Balance / Q000187:drug effects; D011187:Posture
D000927:Anticonvulsants; D000077287:Levetiracetam; D010889:Piracetam