Beta-blockers and sleep: a controlled trial

Area of Science:

• Pharmacology
• Sleep Medicine
• Neuroscience

Background:

• Beta-blockers are widely prescribed cardiovascular drugs.
• Their effects on sleep are not fully understood, with varying reports in literature.
• Lipophilicity is hypothesized to influence central nervous system penetration and subsequent sleep effects.

Purpose of the Study:

• To investigate the effects of four beta-blockers (atenolol, propranolol, metoprolol, pindolol) on sleep quality and physiology.
• To compare the effects of lipophilic versus hydrophilic beta-blockers on sleep parameters.
• To explore the relationship between subjective sleep reports and objective physiological measurements.

Main Methods:

• A placebo-controlled, randomized crossover trial involving 10 female volunteers.
• Each subject underwent five 10-night test periods (baseline, low dose, high dose, withdrawal).
• Sleep quality was assessed via daily questionnaires, and physiological data (EEG, eye movement, heart rate, muscle tension) were recorded nightly.

Main Results:

• Subjective reports indicated increased dreaming and awakenings with the lipophilic beta-blockers (propranolol, metoprolol, pindolol).
• Objective recordings confirmed increased awakenings with lipophilic drugs and reduced REM sleep frequency for all tested beta-blockers.
• The hydrophilic beta-blocker, atenolol, did not affect subjective sleep but reduced REM frequency.

Conclusions:

• Increased awakenings caused by lipophilic beta-blockers may lead to enhanced recall of dreaming, explaining paradoxical subjective findings.
• Reduced REM sleep frequency by beta-blockers, including the hydrophilic atenolol, suggests potential central or peripheral mechanisms influencing sleep architecture.
• Beta-blocker lipophilicity plays a role in subjective sleep disturbances, while REM sleep reduction appears common across different types.