27.12.2012 Views

A Textbook of Clinical Pharmacology and Therapeutics

A Textbook of Clinical Pharmacology and Therapeutics

A Textbook of Clinical Pharmacology and Therapeutics

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

<strong>and</strong> daytime sleeping should be discouraged. Increased<br />

daytime exercise improves sleep at night.<br />

• Alcohol should be avoided because it causes rebound<br />

restlessness <strong>and</strong> sleep disturbance after the initial sedation<br />

has worn <strong>of</strong>f. Tolerance <strong>and</strong> dependence develop rapidly.<br />

It also causes dehydration (gueule de bois) <strong>and</strong> other<br />

unpleasant manifestations <strong>of</strong> hangover.<br />

SPECIAL PROBLEMS AND SPECIAL GROUPS<br />

JET LAG<br />

Jet lag consists <strong>of</strong> fatigue, sleep disturbances, headache <strong>and</strong> difficulty<br />

in concentrating. It is due to mismatching <strong>of</strong> the body clock<br />

(circadian dysrhythmia) against a new time environment with<br />

its own time cues (Zeitgebers). Resetting the internal clock is hastened<br />

by conforming to the new time regime. Thus, one should<br />

rest in a dark room at night, even if not tired, <strong>and</strong> eat, work <strong>and</strong><br />

socialize during the day. Sufferers should not allow themselves<br />

to sleep during the day (easier said than done!). Taking hypnotics<br />

at night can make things worse if sleepiness is experienced<br />

the next day. However, short-acting benzodiazepines may be<br />

effective if taken before going to bed for two or three nights.<br />

Melatonin is <strong>of</strong> uncertain usefulness but may help sleep<br />

patterns, <strong>and</strong> improves daytime well-being if taken in the<br />

evening. It is not generally available in the UK, although it is<br />

in several other countries including the USA.<br />

NIGHT WORK<br />

Night work causes more serious sleep difficulties than jet lag<br />

because hypnotics cannot be used for long periods. Moreover,<br />

drug-induced sleep during the day precludes family <strong>and</strong> other<br />

non-work activities. A better strategy is to allow the subject to<br />

have a short, non-drug-induced sleep during the night shift.<br />

This improves efficiency towards the end <strong>of</strong> the night shift <strong>and</strong><br />

reduces sleep needs during the day.<br />

CHILDREN<br />

The use <strong>of</strong> hypnotics in children is not recommended, except<br />

in unusual situations (e.g. on the night before an anticipated<br />

unpleasant procedure in hospital). Hypnotics are sometimes<br />

used for night terrors. Children are, however, prone to experience<br />

paradoxical excitement with these drugs. Promethazine,<br />

an antihistamine which is available without a prescription, is<br />

<strong>of</strong>ten used, but is <strong>of</strong> doubtful benefit.<br />

ELDERLY<br />

Anxiety <strong>and</strong> insomnia are prevalent in the elderly, for a variety<br />

<strong>of</strong> psychological <strong>and</strong> physical reasons. As a rule, elderly<br />

patients are more sensitive to the action <strong>of</strong> central nervous system<br />

(CNS) depressant drugs than younger patients, <strong>and</strong> the<br />

pharmacokinetics <strong>of</strong> these drugs are also altered such that their<br />

action is more prolonged with increasing age. Hypnotics<br />

increase the risk <strong>of</strong> falls <strong>and</strong> nocturnal confusion. Even shortacting<br />

drugs can lead to ataxia <strong>and</strong> hangover the next morning.<br />

In the treatment <strong>of</strong> insomnia, when short-term treatment<br />

with drugs is considered necessary, short-acting hypnotics<br />

should be used in preference to long-acting drugs but with<br />

ANXIETY 107<br />

explanation from the outset that these will not be continued<br />

long term. (Short-acting benzodiazepines have the greatest<br />

abuse potential.) Insomnia occurring in the context <strong>of</strong> documented<br />

psychiatric disorders or dementia may be better<br />

treated with low doses <strong>of</strong> antipsychotic drugs.<br />

Case history<br />

A 42-year-old man with chronic depression presents to his<br />

general practitioner with a long history <strong>of</strong> difficulty in sleeping<br />

at night, associated with early morning waking. His general<br />

practitioner had made the diagnosis <strong>of</strong> depression <strong>and</strong><br />

referred him some years previously for cognitive behavioural<br />

therapy, but this had not resulted in significant improvement<br />

<strong>of</strong> his symptoms. His difficulty in sleeping is now interfering<br />

with his life quite significantly, so that he feels tired most<br />

<strong>of</strong> the day <strong>and</strong> is having difficulty holding down his job as<br />

an insurance clerk. The GP decides that he would benefit<br />

from taking temazepam at night; he prescribes him this,<br />

but says that he will only give it for a maximum <strong>of</strong> a month,<br />

as he does not want his patient to become addicted.<br />

Question 1<br />

Is this the correct management?<br />

Question 2<br />

What would be a suitable alternative treatment?<br />

Answer 1<br />

No. Although the benzodiazepine might help in the short<br />

term, it does not provide the patient with a long-term solution,<br />

<strong>and</strong> does not tackle the root cause <strong>of</strong> his insomnia.<br />

Answer 2<br />

A more appropriate treatment would be with a regular<br />

dose <strong>of</strong> a sedating antidepressant drug, for example amitriptyline<br />

at night.<br />

ANXIETY<br />

Anxiety is fear <strong>and</strong> is usually a normal reaction. Pathological<br />

anxiety is fear that is sufficiently severe as to be disabling. Such<br />

a reaction may be a response to a threatening situation (e.g. having<br />

to make a speech) or to a non-threatening event (e.g. leaving<br />

one’s front door <strong>and</strong> going into the street). Episodes <strong>of</strong> paroxysmal<br />

severe anxiety associated with severe autonomic symptoms<br />

(e.g. chest pain, dyspnoea <strong>and</strong> palpitations) are termed panic<br />

attacks <strong>and</strong> <strong>of</strong>ten accompany a generalized anxiety disorder.<br />

GENERAL PRINCIPLES AND MANAGEMENT OF<br />

ANXIETY<br />

• Distinguish anxiety as a functional disturbance from a<br />

manifestation <strong>of</strong> organic brain disease or somatic illness<br />

(e.g. systemic lupus erythematosus).<br />

• Assess the severity <strong>of</strong> any accompanying depression,<br />

which may need treatment in itself.<br />

• Most patients are best treated with cognitive therapy,<br />

relaxation techniques <strong>and</strong> simple psychotherapy <strong>and</strong><br />

without drugs.<br />

• Some patients are improved by taking regular exercise.<br />

• In severely anxious patients who are given anxiolytic drugs,<br />

these are only administered for a short period (up to two<br />

to four weeks) because <strong>of</strong> the risk <strong>of</strong> dependence.

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!