Propranolol and alcohol interaction
Pro Research Analysisby 
Searched over 200M research papers
Propranolol and Alcohol Interaction: Enzyme Inhibition and Metabolism
Propranolol, a beta-adrenergic blocker, can interact with alcohol by inhibiting key enzymes involved in alcohol metabolism. Studies show that propranolol reversibly inhibits alcohol dehydrogenase and aldehyde dehydrogenase, which are essential for breaking down ethanol and its toxic byproduct, acetaldehyde. This inhibition could slow down ethanol oxidation and potentially alter the metabolism of alcohol and related compounds in the body . Additionally, propranolol noncompetitively inhibits alcohol dehydrogenase activity in female rats, but not in males, and enhances mitochondrial aldehyde dehydrogenase activity in both sexes. These findings suggest possible gender differences in the interaction and raise concerns about using propranolol in patients who consume alcohol .
Propranolol’s Effects on Alcohol-Induced Behaviors and Physiology
Additive Effects on Hypothermia and Sleep
Research in mice indicates that propranolol and alcohol together have an additive hypothermic effect, which slows the rate at which alcohol is cleared from the body. This interaction is influenced by genetic factors, as some mouse strains are more sensitive to the combined effects than others. However, propranolol does not appear to change the central nervous system’s sensitivity to alcohol’s hypnotic (sleep-inducing) effects .
Impact on Cardiac Protein Synthesis
Alcohol is known to reduce cardiac protein synthesis, contributing to its cardiotoxic effects. Propranolol does not prevent this reduction; in fact, propranolol alone may further disturb protein synthesis in the heart, especially in the right ventricle. This suggests that alcohol’s harmful effects on the heart occur independently of beta-receptor activity .
Cardiovascular Responses During Alcohol Withdrawal
In people undergoing alcohol withdrawal, propranolol’s effects on heart rate and heart function change over time. Initially, propranolol causes a stronger slowing of the heart (bradycardia), likely due to increased drug bioavailability and heightened sympathetic activity. As withdrawal symptoms resolve, the heart’s response to propranolol weakens, possibly due to changes in beta-receptor sensitivity .
Propranolol and Alcohol Consumption: Animal Studies
Suppression of Alcohol Drinking
Propranolol can reduce alcohol consumption in animal models, especially in rats that are dependent on alcohol. Higher doses of propranolol are more effective, and the effect is more pronounced in animals with a history of alcohol dependence. This suppression is not due to general motor impairment, but rather to central actions of propranolol on the brain’s noradrenergic system 789.
Combination Therapy with Prazosin
Combining propranolol with prazosin, an alpha-1 adrenergic blocker, is more effective at reducing alcohol intake than either drug alone. This combination consistently suppresses alcohol drinking during withdrawal and after periods of abstinence, suggesting a potential strategy for preventing relapse in alcohol use disorder 589.
Propranolol’s Influence on Alcohol Intoxication and Cognitive Effects
In human studies, propranolol does not reverse the effects of alcohol intoxication. Instead, it can increase alcohol’s negative impact on divided attention, subjective feelings of inebriation, and brain activity patterns, without changing blood alcohol levels. This suggests that propranolol may enhance some of alcohol’s impairing effects, possibly by reducing the activity of central catecholamine systems .
Conclusion
Propranolol interacts with alcohol at multiple levels, from inhibiting metabolic enzymes to altering behavioral and physiological responses. It can slow alcohol metabolism, enhance some of alcohol’s negative effects, and reduce alcohol consumption in animal models, especially when combined with other adrenergic blockers. However, propranolol may also increase certain risks, such as impaired attention and potential gender-specific effects. These findings highlight the complexity of propranolol and alcohol interactions and suggest caution when considering propranolol use in individuals who consume alcohol.
Sources and full results
Most relevant research papers on this topic