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2009-06-21
HYPNOTIC DRUGS must be prescribed and taken with care


Some people have difficulty in sleeping soundly, and one of the hypnotic drugs can give them a good night's rest. But it must be prescribed and taken with care.

Q Is there a danger in mixing my sleeping pills with a night­time alcoholic drink?

A Yes. The effects of alcohol

add to the effects of all hypnotic drugs and therefore to take both can produce excessive sedation, which may be dangerous. A (small) bedtime drink taken by itself may be the best form of hypnotic, although, of course, the regular use of alcohol can have its own dangers.

Q Are hypnotic drugs dangerous if taken by children?

A It is vital that all drugs, but especially sleeping tablets, be kept out of reach of children. Because of their small body size, children can be killed by even quite small overdoses of hypnotic drugs. There are occasions when a mild hypnotic is needed for a short period to correct a difficult sleep pattern in a child, but the dosage prescribed should be very carefully observed

Q Are there some hypnotic drugs which make you too drowsy to drive?

A Yes. Most of the commonly used hypnotic drugs cause significant drowsiness, lasting for some time after the person appears to have woken from sleep. For this reason anyone taking these drugs should take care not to drive while still under their influence.

Q Is it a bad thing to take sleeping pills for years and years?

A Yes. Through careless prescribing, many people in the past have become addicted, particularly to the barbiturate group of drugs. The problem is that over a period of time, the effects of a certain dose diminish so that more is required to obtain the required effect. In addition, the type of sleep induced by hypnotic drugs is not as refreshing as natural sleep, and so it is better to use a sleeping pill only for a strictly limited period while steps are taken to find out the causes and treat the fundamental cause of the Insomnia.

Sleep difficulties are common and there is a great demand for drugs which will help those who suffer from such problems to have a good night's sleep. Although no hypnotic drug produces normal sleep, some induce sleep that is nearer to natural sleep than others. But some dif­ficulties in sleeping are not likely to be helped by hypnotic drugs at all.

Different types of hypnotic drugs There are various types of sleep- inducing drugs available, but they all tend to have side-effects to some degree.

Chloral derivatives: Chloral hydrate was one of the earliest drugs to be used specifically as a hypnotic. The original chemical is not much used nowadays, but chloral is the main ingredient in a drug called dichloralphenazone, widely pre­scribed in tablet form and especially use­ful to elderly people. Chloral hydrate it­self is rather irritating to the stomach and even the much less irritating dich­loralphenazone has to be avoided by people who have peptic ulcers or delicate stomachs. This group of drugs has an addictive effect when mixed with alcohol. Barbiturates: These used to be used very widely, but now that there are safer, less addictive drugs available, they are being prescribed less and less: their main use now is in injections to produce general anaesthesia.

Barbiturates are significantly habit­forming, even addictive, and they pro­duce quite prolonged 'hangover' effects: anyone who takes them will not be at his or her best for most of the morning after a barbiturate-induced sleep. They are also dangerous in overdose (see Barbiturates, page 1391.

Benzodiazepines: These are safe, even in large overdose and, considering how well they work, have remarkably few side-effects, although they may cause nightmares. However, even the benzo­diazepines can be habit-forming, and if they are withdrawn there may be a re­bound in sleeplessness.

Other hypnotic drugs: A mixed group of non-barbiturate drugs has largely been replaced by the benzodiazepines. One drug which was popular a few years ago was a mixture of two others: a hypnotic, methaqualone, and a sedative anti­histamine, diphenhydramine. It was potent and effective but very dangerous in overdose.

For children, on the rare occasions

when they need a drug with some hypnotic effect, the most useful are the sedative antihistamines, including promethazine and trimeprazine, while for elderly people a safe hypnotic drug is chlormethiazole.

How hypnotic drugs work

The part of the brain responsible for the cycles of sleep and wakefulness is the reticular activating system, a widely spread network of brain cells and their nerve fibres which lace up and down the brain stem (see Brain, pp. 217-191, con­trolling the extent to which the brain is electrically active. Some drugs, such as the barbiturates, suppress the activity of considerable areas of the brain, causing hypnotic effects at low doses and com­plete general anaesthesia at higher doses. Others, such as the benzo­diazepines, do not produce general anaesthesia, even at very high doses.

Dangers and side-effects

The barbiturates are particularly prone to cause a hangover, and it is dangerous to drive until their effects have quite worn off because co-ordination and reflexes are significantly suppressed.

The benzodiazepines were introduced as causing very little of a hangover effect, but, in fact, one of them, nitrazepam, has this side-effect, lasting for up to 20 hours after it is taken.

Another serious side-effect occurs in people with chronic chest complaints: many of the hypnotics, especially the barbiturates. will interfere with their breathing in the night, often to a serious extent, and so it is best for them to avoid the use of all hypnotics.

Some people are allergic to certain drugs in the hypnotic group. It is not usually possible to predict which one will cause the allergic reaction, but if a person has it to one drug in a particular group of hypnotics, he or she will probably be allergic to chemically similar drugs.

The barbiturates can make people­particularly if they are elderly-feel confused, and this can be physically dangerous because it may cause falls. Another problem, again especially of the barbiturates but also of the chloral derivatives, is interaction with other drugs which a person may be taking. It is important for a doctor to know whether a patient is taking an hypnotic drug before prescribing any others.

Taken from The Marshall Cavendish A – Z GUIDE IN WEEKLY PARTS - DOCTOR’S ANSWERS – PART 28, HYPNOTIC DRUGS, Page 770 – 771.

(Sorry - Due to the urgency of education on this site, spelling will be corrected at a later stage….All photos in the script have been left out)


otic drugs, their ~ses and possibl

Drug

Uses

Phenobarluitone

Pentobarbitone

Hypnotic

Qualbarbitone

Hypnotic

Hypnotic

Promethazine

Glutethimide

Skin rashes

Chlormethiazole

Hypnotic, trElatrnelnt

* Prescribed dosages sh'Juld alw,ays to and

771


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