A normal dose of sodium thiopental (usually 4–6 mg/kg) given to a pregnant woman for operative delivery (caesarean section) rapidly makes her unconscious, but the baby in her uterus remains conscious.

[13] Sodium thiopental is not used to maintain anesthesia in surgical procedures because, in infusion, it displays zero-order elimination pharmacokinetics, leading to a long period before consciousness is regained.

Sodium thiopental would have to be given in large amounts to maintain unconsciousness during anaesthesia due to its rapid redistribution throughout the body (as it has a high volume of distribution).

Conversely, obese animals will have rapid recoveries, but it will take much longer for the drug to be entirely removed (metabolized) from their bodies.

Patients with refractory elevated intracranial pressure (RICH) due to traumatic brain injury (TBI) may have improved long term outcome when barbiturate coma is added to their neurointensive care treatment.

In both Belgium and the Netherlands, where active euthanasia is allowed by law, the standard protocol recommends sodium thiopental as the ideal agent to induce coma, followed by pancuronium bromide to paralyze muscles and stop breathing.

A coma is first induced by intravenous administration of 20 mg/kg thiopental sodium (Nesdonal) in a small volume (10 mL physiological saline).

[22] After its use for the execution of Jeffrey Landrigan in the US, the United Kingdom introduced a ban on the export of sodium thiopental in December 2010,[23] after it was established that no European supplies to the US were being used for any other purpose.

[32] Such findings implicate (non-GABAergic) ligand-gated ion channels, e.g. the neuronal nAChR, in mediating some of the (side) effects of barbiturates.

[34] Following a shortage that led a court to delay an execution in California, a company spokesman for Hospira, the sole American manufacturer of the drug, objected to the use of thiopental in lethal injection.

"[35] On January 21, 2011, the company announced that it would stop production of sodium thiopental from its plant in Italy, because it could not provide Italian authorities with guarantees that exported doses would not be used in executions.

[36] In October 2015 the U.S. Food and Drug Administration confiscated an overseas shipment of thiopental destined for the states of Arizona and Texas.

FDA spokesman Jeff Ventura said in a statement, "Courts have concluded that sodium thiopental for the injection in humans is an unapproved drug and may not be imported into the country".

Premedication with sedatives such as benzodiazepines or clonidine will reduce requirements due to drug synergy, as do specific disease states and other patient factors.

[40] Specific disease conditions that can alter the dose requirements of thiopentone and for that matter any other intravenous anaesthetic are: hypovolemia, burns, azotemia, liver failure, hypoproteinemia, etc.

[41] As with nearly all anesthetic drugs, thiopental causes cardiovascular and respiratory depression resulting in hypotension, apnea, and airway obstruction.

Intravenous administration of sodium thiopental is followed instantly by an odor and/or taste sensation, sometimes described as being similar to rotting onions, or to garlic.

However, recent evidence available through freedom of information legislation was reviewed in the British Journal of Anaesthesia,[49] which has suggested that this story was grossly exaggerated.