The Effect of β-Blockers on Mental Performance on Older Hypertensive Patients

This double-blind, three-way crossover study measured the influence of β-blocker treatment on drowsiness and mental test performance in older hypertensive patients and determined if lipophilicity was a determinant of these effects. Twenty-seven hypertensive patients (mean age, 63±3 years) were studied. Patients received two weeks each of daily treatment with placebo, 100 mg of atenolol, or 150 mg of metoprolol tartrate and were evaluated on the 14th day of each treatment period, after which their next treatment period began. Mental performance was measured using Trails-A maze testing. Drowsiness was measured subjectively using a visual analogue scale, and objectively using critical fusion-frequency threshold testing. Blood pressure control was equivalent and clinically adequate in all subjects. Steady-state levels of metoprolol tartrate (235±46 ng/mL) and atenolol (453.6±56 ng/nL) achieved were those expected to produce similar β-blockade. Mental performance as measured by Trials-A testing showed better scores during β-blocker treatment compared with placebo. Trails-A scores improved as patients went from placebo to metoprolol treatment, but did not change as patients went from placebo to atenolol treatment. Critical fusion-frequency threshold measurements were lower following administration of both drugs than following that of placebo, but subjectively there was no difference in feelings of lethargy between either β-blocker and placebo. These data show greater improvement in mental testing performance to be associated with metoprolol treatment, but neither produced more lethargy than placebo in elderly patients.