Beta-blockers and anxiety

During the 1990s, with concern over benzodiazepine use, there was interest in the use of beta-blockers in the treatment of anxiety. The principal drugs in this group used psychiatrically are shown in Table 12.1.

**Table 12.1** Beta-blockers used psychiatrically
Generic drug name	UK trade name	US trade name
Propranolol	Inderal/Beta-Prograne	Inderal
Atenolol	Tenormin	Tenormin

Beta-blockers are used mainly in the treatment of hypertension, angina and cardiac arrhythmias. The rationale for their use in psychiatry is that they block the peripheral manifestations of anxiety, such as increased heart rate or shaking in the hands. Signs such as these are the cues we all use to judge how anxious we are. When these effects of anxiety are controlled, it seems that two sets of feedback loops may be interrupted. Part of getting anxious involves getting anxious at signs that one is getting anxious, such as increased heart rate and shaky hands. These manifestations of anxiety can lead to worries in their own right, for example the concert performer who may worry about both the audience and the effects of a shaky hand on the violin bow. Similarly, public speakers may have their nervousness made worse by the effects of a tremulous voice or a dry mouth in the act of speaking. Controlling effects such as heart rate, voice timbre and hand steadiness, therefore, can take away one set of stimuli to further anxiety, and indeed ease central anxiety by removing the cues by which we all judge just how anxious we are.

PERFORMANCE-RELATED ANXIETY

The role of beta-blockers in the management of anxiety was highlighted by their use by musicians experiencing stage fright, who find that by using them they are able to cope with being on stage and to give more assured performances than they would otherwise have been able to give. Up to a third of orchestral musicians have been reported to use beta-blockers to steady their hands or control palpitations. They were also used by snooker players, supposedly for medical conditions, but in actual fact they often seem to reduce the amount of shake in a cue arm, allowing the player to hit the ball more surely. ²⁰

As little as 10mg of propranolol per day may be all that is needed to block the manifestations of stage fright of this type. Doses greater than 40mg are rarely needed.

GENERALISED ANXIETY DISORDER

With concern about the use of benzodiazepines, general practitioners began to prescribe beta-blockers for many of their more diffusely anxious patients during the 1990s. The rationale for this is much more tenuous than using these drugs for stage fright. In stage fright, treatment is tied to specific situations but this is not the case in generalised anxiety disorder (GAD) and, as a consequence, much larger doses of beta-blockers have tended to be used and for longer periods of time.

The standard dose for propranolol used for GAD has been 20mg four times a day, or 80mg of longer-acting preparations such as Inderal LA (long acting). There have been trials on four beta-blockers for GAD: propranolol, oxprenolol, sotalol and practolol. Practolol has since been withdrawn from widespread use. Sotalol and oxprenolol had no clear anxiolytic effects. Other beta-blockers such as labetalol, metoprolol, timolol, pindolol, nadolol and atenolol have not been investigated for anxiolytic effects.

Propranolol, however, came out as being significantly anxiolytic without causing the sedative effects found with benzodiazepines. It brings about improvements in palpitations, sweating, diarrhoea and tremor. The fact that propranolol is effective raises a further possibility, however, in that propranolol has prominent effects on the serotonin system (see Ch. 11). Given that other beta-blockers are not effective in GAD, it seems quite possible that it is propranolol’s effect on the serotonin system that is helpful.

PANIC ATTACKS: A PUZZLE?

The use of beta-blockers can generally be considered in individuals who have anxiety states characterised by prominent peripheral manifestations of anxiety – increased heart rate, etc. Surprisingly, however, there are no reports of these drugs being beneficial in panic attacks, which are characterised by physical symptoms of disabling intensity.

TREMOR