Understanding Anesthesiology - The Global Regional Anesthesia ...

SODIUM THIOPENTAL
Class
Short-acting barbiturate. Was used as an anesthetic induction
agent but has largely been replaced by propofol.
It is also useful as an anticonvulsant or for the rapid reduction
of elevated intracranial pressure.
Mechanism of action
Decreases the rate of dissociation of the inhibitory neurotransmitter
GABA from its receptors resulting in depression
of the reticular activating system.
Dose
3-5 mg/kg IV for healthy adults
5-6 mg/kg IV for children
7-8 mg/kg IV for infants
Dose must be reduced considerably in unstable or fragile
patients.
Onset
Within one arm-brain circulation time (approximately
20 seconds).
Duration
Approximately 5-10 minutes after single induction
dose.
Elimination
Rapid redistribution of drug from the central nervous
system (CNS) to lean body tissue accounts for the
prompt awakening. The final elimination from the
body depends on hepatic metabolism and excretion by
the kidneys.
Effects
CNS
Profound CNS depressant. Decreases cerebral metabolic
rate and intracranial pressure. May cause hypertonus,
twitching and tremors during induction. May contribute
to post-operative confusion and delirium. Potentiates
the depressant effects of opioids, sedatives, alcohol
and volatile anesthetics.
CVS
Depression of myocardial contractility and vasodilation
leads to decreased cardiac output and blood pressure
with a mild compensatory tachycardia. Must be used
with caution in patients with poor left ventricular function
or critical coronary artery insufficiency or in those
who are seriously ill or debilitated.
Respiratory
Depresses the rate and depth of breathing leading to
brief period of apnea. Does not blunt the airway’s response
to manipulation therefore coughing, hiccoughing,
laryngospasm and bronchospasm may be seen at
light planes of anesthesia.
GI
Nausea and vomiting
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