Sleep and Aging

Sleep takes up 1/4-1/3 of a person's life.

Sleep must therefore fulfill an important function of daily living.

During sleep the body replenishes cellular constituents, several repair processes take place, and the body generally prepares itself for the next day.

The brain assimilates information received the previous day, and the powers of problem solving and concentration are consolidated.

Restful sleep enables us to have a feeling of well being and comfort.

There are two types of sleep: Rapid Eye Movement (REM) and Non Rapid Eye Movement) which is further subdivided into four stages, 1-4, 1 being the lightest sleep and 4 being the deepest sleep.

During NREM sleep there are periodic movements of the body, but other body functions are slowed down.

During REM sleep is when most people experience dreams, there are periodic muscle twitches but the body is essentially paralyzed during this type of sleep.

As people age we experience changes in sleep patterns. These changes are normal.

- require longer time to fall asleep

- sleep lighter

- experience more awakenings

- periods of REM sleep become fewer

There are several medical conditions which can alter normal sleep pattern.

asthma	emphysema
depression	cystic fibrosis
head injury	epilepsy
headache	pain
stroke	Parkinson's disease
Huntington's chorea	Tourette syndrome
dementia	MI
angina	arthritis
chronic renal failure	hyperthyroidism
"heart burn"

We need to rule out the presence of any one of these conditions, and treat whichever is present in order to establish normal sleep pattern.

There are also a number of drugs which can cause insomnia

some types of anti-depressant drugs SSRI's, MAOI's, TCA's	sleeping pills (withdrawal after chronic use)
thyroid hormone	theophylline
phenytoin	levodopa
methyldopa	diuretics
decongestants	amphetamines
cigarette smoking	alcohol
caffeine

Once we have established that we have ruled out any of the above as the cause of the altered sleep pattern, and before we resort to drug therapy, it is important to try some non-medical intervention.

Develop better sleep hygiene.

The recommendations are:

• exercise in late afternoon or early evening- keep it light so as not to overstimulate the body to the point where relaxing becomes difficult

• abstain from caffeine containing beverages or alcohol after dinner

• avoid cigarettes- nicotine is a stimulant

• have a light snack or warm glass of milk ( people with hiatus hernia should not go to sleep immediately after they eat, and should elevate the head of the bed.)

• engage in relaxing activities- read, watch TV, listen to music

• keep room temperature at 17 degrees (65 F)

• only go to bed when sleepy

• if can't get to sleep don't toss and turn, get up and do something relaxing

• get up at the same time each morning- including weekends

• if excessive urination at night is a problem, restrict fluid intake before bedtime

Having exhausted all of the above non-medical interventions we can now consider drug therapy.

The ideal drug

• should be effective

• have quick onset of action

• should not accumulate

• should have no active metabolites

• have no residual effect

• have no drug dependency

and would benefit the patient by

• reducing the time it takes to fall asleep

• decrease the number of awakenings

• increase total sleep time

• increase sleep efficiency

THE IDEAL SLEEP AGENT HAS NOT YET BEEN DISCOVERED

Advantages and disadvantages of frequently used agents

Agent	Advantages	Disadvantages
Chloral Hydrate (Noctec)	Proven efficacy, no sleep distortion	tolerance develops, potential for drug interactions, toxic at 2-4 times therapeutic dose
Antihistamines (Nytol, Sominex, Gravol)	variable response	paradoxical effects- especially in elderly, tolerance, side effects
Ethchlorovynol (Placidyl)	proven efficacy	drug interaction, tolerance after 1 wk
Benzodiazepines (diazepam, oxazepam, lorazepam etc)	safe, efficacious	see separate table
Barbiturates (Tuinal, Seconal, Phenobarbital)	proven efficacy	tolerance develops, distort sleep pattern, low therapeutic index, interactions, respiratory depression

Anti-depressants (TCA's, Trazodone ) are sometimes used as sleep aids in non-depressed patients due to a sedative side effects of the drugs. The doses are usually much smaller than those used to treat depression.

Some of them have (anticholinergic) side effects, can cause memory impairment, increase heart rate, or cause orthostatic hypotension.

Zopiclone (Imovane) although chemically is different from the benzodiazepines, is thought to exert its effect the same way that the benzodiazepines do.

It is the drug which is the closest to those I have described to be for the ideal hypnotic.

Short onset of action

Short elimination half life (8 hrs in elderly)

Little risk of accumulation

Information on residual effect is conflicting

Side effects mild- dry mouth, difficult rising in am, bitter taste- reduced with a glass of orange juice but not milk.

Disadvantage- Relatively expensive

Melatonin- has been written and talked about in the media recently.

Melatonin is a hormone we produce and secrete at night. The levels of Melatonin normally are highest during normal hours of sleep and decrease toward morning.. Older people who suffer from irregular sleep-wake cycle have lower levels of Melatonin.

Several studies seem to indicate that taking Melatonin may help with insomnia and jet lag symptoms.

Problems- it is marketed as a food supplement and not a drug, and therefore not subject to the same stringent regulations governing medicinals. There is no guarantee of purity, or even that it contains the amount claimed on the label.

Also, optimal dose has not yet been established, no studies of effects after long term use, or interactions with other drugs.