Addiction Treatment Blog

Beta-blockers

In recent years, with concern over benzodiazepine use, there has been interest in the use of beta-blockers in the treatment of anxiety, principally propranolol (Inderal) and atenolol (Tenormin). Although they 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 becoming anxious involves anxiety at signs of becoming anxious, such as increased heart rate and shaky hands. These manifestations of anxiety can lead to worries in their own right, for example, for the concert performer who may worry about both the audience and the effects of shaky hand on the violin bow. Similarly public speakers may have their nervousness faced with an audience augmented by nervousness about the effects of tremulous voice or a dry mouth on the act of speaking itself. Controlling effects such as heart rate, voice timbre and hand steadiness, therefore, can interrupt one feedback loop by taking away a set of stimuli to further anxiety. It can also interrupt another and ease the central anxiety by, as it were, removing the cues by which we all judge just how anxious we are.

Table of Contents

• Performance-related Anxiety
• Generalised Anxiety Disorder (GAD)
• Panic Attacks: A Puzzle?
• Tremor
• Akathisia / Restlessness
• Side Effects of Beta-blockers
• References
• Do You Need Help?

Performance-related Anxiety (1)

The role of beta-blockers in the management of anxiety has been highlighted 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 do. Up to 1/3 of orchestral musicians have been reported to use beta-blockers in order to steady their hands or control palpitations. There is somewhat more notorious use for beta-blockers by snooker players, who have been using them supposedly for medical conditions, but who in actual fact may have been using them to minimise the effects of anxiety: in particular to reduce the amount of shake in their cue arm, allowing them to hit the ball more surely.

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

Generalised Anxiety Disorder (GAD)

With increasing concern about the use of benzodiazepines for anxiety, general practitioners have in recent years taken to prescribing beta-blockers for many of their more diffusely anxious patients. The rationale for this is tenuous. In the case of stage-freight there is a very clear rationale and treatment is tied to specific situations. This is not possible with 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 generalised anxiety disorder has been 20 mg four times a day or 80 mg of longer-acting preparations such as Inderal LA (long-acting). There have been trials on four beta-blockers for generalised anxiety disorder, propranolol, oxprenolol, sotalol and practolol. Practolol has since been withdrawn from widespread use. Sotalol and oxprenolol had no clear anxiolytic effects. Propranolol, however, has come out as being significantly anxiolytic, without causing the sedative effects found with benzodiazepines. It brings about significant improvement in palpitations, sweating, diarrhoea and tremor.

There are a number of other beta-blockers such as labetalol, metoprolol, timolol, pindolol, nadolol and atenolol that may also have anxiolytic effects but these have not been investigated systematically yet. The fact that propranolol is particularly effective raises, however, a further possibility in that propranolol has prominent effects on the 5-HT system. Given that other beta-blockers are not particularly effective in GAD, it seems quite possible that it propranolol’s effect on the 5-HT system that is helpful. If this is the case, then a more specific 5-HT drug probably should be used instead as the beta-blockers, propranolol included, may in their own right cause significant rebound anxiety on discontinuation.

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 their being beneficial in panic attacks which are characterised by physical symptoms of disabling intensity.

Tremor

The beta-blockers are also of use for lithium induced tremor and for a number of neuroleptic induced dyskinesias.

Akathisia / Restlessness

Propranolol, but not other beta-blockers, may also be of significant benefit in states of akathisia, unresponsive to anticholinergic compounds. It also seems to be of some benefit in SSRI induced akathisia or dyskinesias.

Side Effects of Beta-blockers

• All beta-blockers can cause shortness of breath. They should therefore be used with caution in anyone who has a history of wheeze or asthma.
• Beta-blockers can also cause reduced circulation of blood to the extremities. In cold weather this may lead to painful and cold fingers, which may in their own right interfere with performances requiring dexterity, such as playing music, for example.
• They also reduce circulation of blood to muscles and on this basis may need to be used with caution for performance-related anxiety. While they may be useful to snooker players and musicians they are, if anything, likely to be unhelpful to dancers and singers, because they may cause wheezing or shortness of breath and, for the former because they reduce blood flow to muscles that may be needed for use. They may also inhibit performance by dropping blood pressure, leading to fainting.
• Some individuals have difficulties with sleep and nightmares on beta-blockers, especially propranolol. The reason for this is uncertain.
• Tiredness and lassitude are sometimes reported. This may be allied to a clear feeling of muscle weakness on exertion. There is no clear sedative effect of these compounds, however, and no indication that they interfere with ability to drive for instance.
• Poor concentration and memory disturbances have also been reported. Propranolol does seem to reduce short-term memory span, even in healthy control subjects. This is different to the effects of benzodiazepines on memory, which involve not being able to recall things afterwards. Beta-blockers involve not being able to take in as much as usual at any one time.
• In common with many other centrally acting compounds, beta-blockers can cause dissociative effects, including hallucinations and confusion.
• In high doses, beta-blockers may cause nausea and vomiting, diarrhoea, dry eyes and skin rashes, but such doses should never be needed for the control of anxiety.
• Beta-blockers may interact with other drugs used for heart disease or hypertension, including clonidine and calcium channel blockers such as verapramil.

References

1. Wheatley D: The anxiolytic jungle; where next? Chichester: JW Wiley and Sons; 1990.