[Histamine and the convulsive threshold or effectiveness of antiepileptic drugs].

BACKGROUND: A problem of influence of antihistaminic drugs upon the convulsive threshold and effectiveness of antiepileptic drugs appears significant because of the increasing prevalence of allergic diseases in 21st century which results in significant intake of anti-allergic drugs. Existing experimental data provide data on the possible interactions between antiepileptic and antihistaminic drugs.

THE AIM OF STUDY: To characterize the importance of histamine and anti-histaminic drugs in seizure susceptibility and evaluate interactions between antiepileptic and antihistaminic drugs.

RESULTS: Histamine, apartfrom its various activities, takes also part in the inhibition of seizures via H1 histamine receptors. H1 receptor antagonists (antazoline, ketotifen, astemizole), especially when administered chronically, impaired the anticonvulsant activity of some antiepileptic drugs (phenobarbital, phenytoin, valproate) against maximal electroshock-induced convulsions in mice. Valproate was resistant to this hazardous effect of antihistaminic drugs.

CONCLUSION: It may be postulated that a possible use of antihistaminic drugs in epileptic drugs needs to be carefully considered in terms of risk/benefit ratio.