Sodium Pentathol is Abbott Laboratories brand name for sodium thiopental, a barbiturate. In its typical form it is a yellowish-white hygroscopic powder having a garlic-like odor. It is soluble in water and alcohol. It is used in medicine as a fast-acting general anesthetic.[1] It is often used as part of the process of execution by lethal injection.[2]
Sodium Pentathol makes the neural membrane more permeable to chloride ions, resulting in general inhibition, starting with the cortex and working down to the lower brain regions with increasing biological effect. Because of its effects it is known as a truth serum and used in interrogation.[3]
At an appropriate dosage, a patient experiences a neural inhibitory effect which creates an alcohol-like disinhibition of normal behavioral restraints. At higher dosages, but not high enough to cause unconsciousness, a patient may experience a stupor and Sodium Pentathol may inhibit independent thought and action to a greater extent. The result makes the patient more suggestible and less willful. Under such circumstances, a context for either recalling memories or constructing new ones may then be created. The actual veracity of the testimony achieved in this manner may be impossible to determine from a single session alone. There is some overlap in interrogation with the practice of using ethyl ether to aid in obtaining a psychodynamic 'catharsis,' which may or may not relate to actual events in the patient's personal history, and overlap with some aspects of the use of hypnosis for similar purposes.