10. MANAGEMENT
10.1 General principles
General supportive measures should be used. These
should include stabilisation of the airway, breathing, and
circulation; relief of agitation, adequate hydration, and
control of core temperature. Convulsions, hyperthermia, and
rhabdomyolysis may require specific treatment. Activated
charcoal may be helpful for decontamination after oral
ingestion. Ipecacuanha is contra-indicated because of its
stimulant properties. There are no effective methods of
enhancing elimination and no antidote.
Agitation and convulsion can be treated with diazepam. If
agitation is severe, then chlorpromazine may have specific
advantages over other major tranquillisers (Espelin & Done,
1968; Klawans, 1968). Parenteral dosages of 0.5 to 2
milligrams per kilogram have been used in Infants (Espelin &
Done, 1968).
Severe hyperthermia (core temperature greater than 40°C)
requires forced cooling by fans, tepid sponging or other
means, and may also require the administration of diazepam or
dantrolene or both agents in order to eliminate muscle
activity.
Rhabdomyolysis associated with muscle overactivity can cause
hyperkalaemia or renal failure, and should be treated
conventionally. Dialysis may be needed if renal failure
supervenes.
Acute severe hypertension (diastolic blood pressure greater
than 100 mmHg) can be controlled by infusion of sodium
nitroprusside by continuous intravenous infusion at an
initial rate of 3 mcg/kg/min, titrated to achieve the desired
response.
Patients who are addicted to amphetamines may develop the
withdrawal syndrome described in 9.5.
10.2 Life supportive procedures and symptomatic/specific
treatment
Treatment is supportive. Administration of
supplemental oxygen, establishment of intravenous access and
monitoring of vital signs including core temperature, and
cardiac rhythm are recommended. The following may be
necessary according to clinical indication:
-Maintenance adequate airway and ventilation
-Rehydration with intravenous fluids
-Control of seizures
-Control of agitation with benzodiazepines
-Control of severe hypertension (diastolic blood pressure
greater than 110 mmHg)
-Control of hyperthermia
-Treatment of hyperkalaemia
-Cardiac intensive care for ischaemia or arrhythmia
10.3 Decontamination
No regime of oral decontamination has been demonstrated
to improve outcome. Ipecacuanha is contra-indicated. Oral
activated charcoal may be helpful following oral overdosage.
10.4 Enhanced elimination
No regime of decontamination has been demonstrated to
improve outcome. Forced acid diuresis has been abandoned as a
decontamination procedure. Neither haemodialysis nor charcoal
haemoperfusion is likely to be of benefit.
10.5 Antidote treatment
10.5.1 Adults
There is no antidote to amphetamine poisoning.
10.5.2 Children
There is no antidote to amphetamine poisoning.
10.6 Management discussion
There are differences between dexamphetamine and
related compounds such as 3,4-methylenedeoxymetamphetamine
(”ecstacy”); for example, hyperthermia appears to be more of
a problem with the latter, and this may be because of the
association between use and frenetic physical activity
(”rave” dancing) (Henry et al., 1992).
In the past, energetic gastric decontamination procedures
were suggested (Espelin & Done, 1968). There is no evidence
that such procedures improve outcome in amphetamine
poisoning, and they are potentially hazardous.
Oral activated charcoal is probably the safest option for
decontamination, but is only likely to bind drug in the
stomach if a substantial oral dose of amphetamine has been
taken, and the charcoal is given within an hour or two of
ingestion. If should only administered to patients in whom
swallowing and gag reflexes are intact. In drug smugglers who
have swallowed supposedly inert packages of amphetamines
(”stuffers” or “packers”), and who develop symptoms because
of leakage from the packages, then repeated doses of oral
activated charcoal with a cathartic are likely to be
worthwhile.
Forced acid diuresis has now been abandoned as an elimination
treatment, because it is intrinsically difficult and
potentially dangerous.
Treatment of agitation in amphetamine poisoning is required
when a patient is a danger to himself or herself, or to
others. Because poisoning is associated with sympathetic
overactivity, and chlorpromazine has alpha-adrenoreceptor
antagonist actions, chlorpromazine has been recommended as
the sedative treatment of choice (see 10.1). There is no
study to demonstrate that chlorpromazine is in fact superior
to benzodiazepine.
