Effects of terfenadine on psychomotor performance. An overview

Sedation and impairment of psychomotor performance are well known adverse effects of the traditional antihistamines. These effects appear to be caused by different mechanisms, but both may have potentially dangerous consequences. while several of the newer antihistamines, such as terfenadine, have overcome the problem of sedation, it is also important to establish their propensity to cause psychomotor impairment. Many single- and multiple-dose studies (mostly in healthy volunteers) have compared the effects of terfenadine on psychomotor performance with those of placebo, as well as traditional and other nonsedating antihistamines. Over half of the studies employed divided-attention tasks that are considered relevant to everyday activities, such as driving. Like several other nonsedating antihistamines, single doses of terfenadine of up to 120 mg did not impair driving performance and generally had no significant effects on other psychomotor tests compared with placebo. In most of the multiple-dose studies, terfenadine 60 mg twice daily was administered for up to 5 days. Again, the effects of terfenadine on psychomotor performance differed little from those of placebo. Thus, the available evidence suggests that the problem of impaired psychomotor performance associated with the older, traditional antihistamines does not apply to terfenadine.