Central Nervous System Effects of Beta-adrenergic-blocking Drugs: the Role of Ancillary Properties

Among the side effects commonly reported with the use of beta-blockers are symptoms related to the central nervous system (CNS). In this study we compared the effects of four beta-blockers with different ancillary properties (atenolol, metoprolol, propranolol, and pindolol) and placebo on objective and subjective measures of CNS function in 30 healthy male subjects. All subjects were randomly assigned to a double-blind, placebo controlled, Latin-square design study in which five 1 week periods of drug or placebo administration were separated by 2 week washout periods. Laboratory evaluations were conducted at the end of each treatment period, and included multistage exercise stress testing; questionnaire assessments of mood state, sexual function, and sleep habits; tests of psychomotor function; and overnight polysomnographic measures of sleep. Significant effects on sleep continuity were observed for each of the lipophilic drugs, as reflected in the number of awakenings (pindolol = 6.4 +/- 5.0; propranolol = 6.3 +/- 3.2; metoprolol = 7.2 +/- 4.7; atenolol = 3.6 +/- 2.9; placebo = 3.9 +/- 2.7) and time of wakefulness (pindolol = 20.6 +/- 27.0 min; propranolol = 15.5 +/- 23.0 min; metoprolol = 19.5 +/- 24.3 min; atenolol = 10.2 +/- 11.6 min; placebo = 9.2 +/- 74.5 min). Only pindolol significantly affected rapid eye movement (REM) sleep time (pindolol = 54.5 +/- 21.9 min; placebo = 74.5 +/- 74.5 min) and REM latency (pindolol = 175.0 +/- 60.7 min; placebo = 95.4 +/- 43.8 min). Subjective reports of sleep similarly indicated increased wakefulness and greater restlessness with lipophilic beta-blockers.(ABSTRACT TRUNCATED AT 250 WORDS)