Beta blockers do not have Food and Drug Administration approval to treat anxiety, though many doctors prescribe it as an "off-label" use. These drugs more often treat various cardiovascular conditions. Beta blockers calm or even stop the physical symptoms of anxiety such as rapid heart rate, shaking voice, tremor and shaking of extremities. According to MayoClinic.com, they work best when used occasionally to control anxious symptoms, clinically known as social anxiety, in a particular situation, such as performing or public speaking. Physiologically, beta blockers bind to and block the beta adrenergic receptors, which are activated by adrenaline and norepinephrine.
Non-Selective Agents
The human body has two types of beta receptors, within different bodily systems. Non-selective beta blockers act on both types of beta receptors, thus controlling all types of physical symptoms of anxiety. Propanolol, a non-selective agent, is the most commonly used beta blocker for treating social anxiety. Other non-selective beta blockers include alprenolol, labetalol and penbutolol.
Selective Agents
Selective agents target beta-1 receptors, those found in the brain and in the heart. These drugs do not easily pass the blood-brain barrier, and thus cause fewer side effects. Drugs in this class include atenolol, nebivolol and bisoprolol. Because they do not act on beta-2 receptors, they exert less control over respiratory symptoms and flushing.
Considerations
At higher doses, propranolol and other beta-blockers that cross the blood--brain barrier may cause unpleasant side effects including depression, fatigue and even delirium. For patients taking hypertensive medications, beta-blockers may be contraindicated. People with certain cardiac or respiratory conditions should not take beta blockers. Unlike some anxiety medications, beta blockers pose no danger of dependence.
