Second edition

21.qxd 3/10/08 9:58 AM Page 662
662 Substance use disorders
Clinical features
Alcohol intoxication of mild degree is characterized by
euphoria, talkativeness, and a degree of disinhibition; in
some patients there may be some irritability or dysphoria
rather than euphoria. In moderate intoxication, the behavior
becomes coarse and the thinking is slow and unclear.
There is facial flushing, conjunctival injection, dysarthria,
nystagmus, and ataxia. With severe intoxication there is
drowsiness, stupor, and disabling ataxia; coma may ensue,
with respiratory depression and death.
The blood alcohol level (BAL) is customarily reported in
milligrams/deciliter or, as it is often worded, milligrams
percent (mg%). In an alcohol-naive subject, mild intoxication
is seen at 100 mg%, moderate intoxication at 200 mg%,
and severe intoxication at 300 mg%; in the alcohol-naive
patient, levels of 400 mg% generally cause coma, and levels
of approximately 500 mg%, respiratory depression.
In general, in a 70-kg subject, the rapid consumption of
15 mL of pure, 100% ethanol will elevate the BAL by about
15–20 mg%, and this amount of pure ethanol is generally
found in one mixed drink, one can of beer, or one glass of
wine. In those with normal hepatic function, ethanol is
metabolized at a rate of 5–10 mL/hour. Of interest, females
tend to become intoxicated with a smaller amount of
ingested alcohol than males, and this may be because of a
reduction in gastric alcohol dehydrogenase activity, thus
allowing a greater percentage of the ingested alcohol to
escape this initial metabolic step (Frezza et al. 1990).
After the intoxication has passed, patients may experience
a ‘hangover’, which may last from hours up to a day.
This is characterized by headache, malaise, dysphoria, nausea,
mild tremulousness, and diaphoresis.
Blackouts may occur during moderate or severe alcohol
intoxication and consist of transient episodes of anterograde
amnesia, lasting anywhere from minutes to days,
depending on how long the BAL remains high (Goodwin
1971; Goodwin et al. 1969a). During a blackout, patients’
behavior may, to casual inspection, not appear to be
changed: patients may recall what they were doing at the
start of the blackout and may also be able to keep track of
ongoing events sufficiently well that they are able to keep
up a conversation, play cards, etc. If, however, short-term
memory is tested during the blackout, one finds that
patients are unable to recall anything that happened much
more than 5 minutes earlier. Furthermore, once the blackout
ends, the time period covered by the blackout remains
an ‘island of amnesia’ to patients, who can recall little or
nothing of the events that transpired during the blackout.
Should blacked-out patients fall asleep during the blackout,
they may, upon awakening the next day, anxiously ask
acquaintances what they did the night before. Those who
are still awake when the blackout abruptly ends may be
quite startled at their situation; one patient (Goodwin et al.
1969b) ‘found himself dancing with no recollection of what
he had been doing during the previous six hours’. A variant
of blackouts, known as ‘brownouts’, may occur in which
the amnesia is not complete and patients can recall some of
what happened (Tamerin et al. 1971).
Pathological intoxication (Perr 1986), although long
written of (Banay 1944; May and Ebaugh 1953), is a controversial
diagnosis (Coid 1979). Putatively, patients, after
only a small amount of alcohol, undergo a dramatic
change, becoming uncharacteristically irritable and often
violent. One study was able to reproduce these symptoms
in patients thought to have suffered pathologic intoxication
(Maletzky 1976), whereas another was not (Bachy-Rita
et al. 1971); if indeed pathologic intoxication does
exist, it is probably rare.
Tolerance to alcohol typically develops gradually with
chronic, repeated intoxications, and greater and greater
amounts must be drunk to achieve the desired intoxication.
Thus, whereas in the alcohol-naive patient levels of
100 mg% typically cause intoxication, those with tolerance
may need to reach a level of 300 mg% before they begin to
‘feel’ the alcohol; indeed, in some cases alcohol-tolerant
patients may sustain levels of 500 mg% without loss of consciousness
(Adachi et al. 1991; Minion et al. 1989).
Interestingly, late in the course of alcoholism, some
patients may fairly rapidly ‘lose’ their tolerance. In such
cases, patients who had previously been able to consume a
liter of liquor and still be standing may now find themselves
hopelessly and severely intoxicated after only a few
drinks.
Alcohol withdrawal (Isbell et al. 1955), colloquially
known as the ‘shakes’, although generally seen only in alcoholics,
may be seen in anyone who engages in heavy, prolonged
drinking. The symptoms appear gradually,
anywhere from 4 to 12 hours after the BAL has fallen below
the patient’s ‘threshold’ for intoxication. Importantly, this
implies that for some patients, such as alcoholics who have
developed tolerance, withdrawal symptoms may appear
while the patient is still drinking, provided that the alcohol
consumption has ‘slowed down’ sufficiently.
Symptoms include tremulousness, anxiety, easy startability,
poor memory and concentration, fleeting and
poorly formed visual or auditory hallucinations, insomnia
(Johnson et al. 1970), elevated temperature, pulse and systolic
blood pressure, mydriasis, generalized hyper-reflexia,
diaphoresis, nausea and vomiting, and diarrhea. The most
prominent symptom of alcohol withdrawal, however, is
tremor, and it is from this that the syndrome derives its
colloquial name. The tremor is postural, rapid, and ranges
in amplitude from fine to coarse; it may be confined to the
outstretched hands or be more widespread, even generalized,
involving the eyelids and tongue in severe cases.
Rarely one may see transient myoclonus or chorea.
Most patients recognize that a drink will ‘solve’ their
problem, and many will take some ‘hair of the dog that bit
you’. This does offer temporary relief of the shakes but of
course threatens to set off a vicious cycle.
Alcohol withdrawal generally peaks within a couple of
days and then gradually settles over the next 2 or 3 days.
Among recreational or abusive drinkers, the symptoms