Tolerance and withdrawal hyperexcitability induced in mice by chronic administration of phenaglycodol.

Abstract

SummaryTolerance and withdrawal hyperexcitability were observed to follow the chronic administration of large doses of phenaglycodol (Ultran) in mice. Tolerance was shown by the fact that the threshold-raising effect of this agent is reduced by 50%, as measured by the low-frequency electroshock technic. Withdrawal hyperexcitability was shown by the fact that, 8 hours after the final dose of phenaglycodol, the seizure threshold is reduced by approximately 20%. The clinical implications of these observations are discussed.