Comparison of the effects of astemizole/pseudoephedrine and triprolidine/pseudoephedrine on CNS activity and psychomotor function

The sedative properties of astemizole-D and triprolidine-D were compared in a double-blind, placebo-controlled, repeated-measures design study comprising three experimental treatments, each with a duration of 2 days (n = 12). Sedation was assessed by continuous electroencephalographic measurement (C-EEG), intermittent performance testing and subjective measures. C-EEG monitoring revealed that triprolidine-D produced significantly more daytime sedation and drowsiness than either astemizole-D or placebo (p < 0.05). Intermittent performance testing did not reveal consistent psychomotor deficits. There were no differences from placebo; the only significant findings showed that astemizole-D improved tracking accuracy at T + 65 h (p < 0.05) compared to baseline. Also, when scores were summed across all time points, astemizole-D improved scores significantly in contrast to triprolidine-D for the total scores (p < 0.05). It is concluded that, in contrast to triprolidine-D, astemizole-D does not produce daytime drowsiness or sedation.