Treating Anxiety with either Beta Blockers or Antiemetic Antimuscarinic Drugs: A Review

Beta adrenergic receptor antagonists and antiemetic muscarinic receptor antagonists are useful for mental health in primary care and family medicine settings, as they provide favorable risk/benefit profiles, and especially so relative to benzodiazepines. Beta blockers (e.g., propranolol) prescribed off-label have been known for decades to provide some, albeit limited, anxiolytic benefit for patients affected by social anxiety disorder (social phobia), including performance anxiety. Blockage of adrenaline’s binding to cardiovascular beta adrenergic receptors inhibits tachycardia, reduces blood pressure, and thus diminishes palpitations in acute anxiety and panic. However, beta blockers are not effective against the psychic (CNS) symptoms, such as anxiousness, fear, and avoidance. Another approach involves antiemetic muscarinic receptor antagonists that are available by prescription (e.g., scopolamine) or over-the-counter (e.g., meclizine) for the treatment of non-cardiovascular symptoms that manifest in anxiety disorders. Antiemetic agents inhibit nausea, vomiting, sweating, and in some instances other psychic (CNS) symptoms. The symptoms affected by antimuscarinic agents represent the “inverse” of the symptoms of acute anxiety affected by beta blockers. Thus, anxiety disorders can be treated by alternative biochemical pathways, as well as by affecting alternative symptoms thereof. The results of human clinical studies are summarized for both classes of anxiolytic agents that display complementary pharmacologic approaches to a diverse array of symptoms.