Sedation and antihistaminics.

A battery of sophisticated studies of central nervous system function in man, including electroencephalogram (EEG) analyses in several laboratories, confirm the numerous clinical reports that alpha-[4-(1,1-dimethylethyl)-phenyl]-4-(hydroxydiphenylmethyl)-1- piperidinebutanol (terfenadine, RMI 9918, Triludan, Teldane, resp.) is devoid of the sedating action characteristic of other antihistamines. No basis has been uncovered for concern about inadvertent overdosage or the operation of machinery while under antihistaminic treatment with terfenadine. Full antihistaminic action is achieved with daily doses totaling 60 to 120 mg. Doses 10 times greater have been shown to be well tolerated in man, indicating a uniquely favorable therapeutic index for an effective H1-inhibitor. In evaluating comparative clinical studies, it is essential to consider whether sedation is factored into the study design as a desired or undesired action.