Study of the CNS side effect of loratadine, a new antihistamine.

ABSTRACT

Loratadine, a derivative of the known antihistamine, Azatadine has been proved to be scarcely distributed to the CNS, having high selectivity for peripheral histamine H1-receptore, hence lacking of CNS depressant effects. Lortadine is an effective antihistamine for the treatment of many allergic diseases. The authors have studied the CNS depressant effects of Loratadine in 35 normal Thai volunteers; 17 males, 18 females, age ranged 20 to 40 years, using a double blind cross over placebo controlled design comparing with chlorpheniramine. The test methods were both subjective and objective i.e. visual analogue scale, alertness rating scale, card sorting test, glassbead picking test, recording of the reaction time test for light stimulation. The CNS side effects of loratadine proved to be differ from those caused by placebo and significantly less than the CNS depressive effect by chlorpheniramine.