|Systematic (IUPAC) name|
|Legal status||Schedule IV (CA) Schedule II/Schedule III (US)|
|Routes||Oral, IM, IV, Rectal|
|CAS number||64-43-7 (sodium salt)|
| (what is this?)
Amobarbital (formerly known as amylobarbitone) is a drug that is a barbiturate derivative. It has sedative-hypnotic properties. It is a white crystalline powder with no odor and a slightly bitter taste. It was first synthesized in Germany in 1923. If amobarbital is taken for extended periods of time, physical and psychological dependence can develop.
In an in vitro study in rat thalamic slices amobarbital worked by activating GABAA receptors, which decreased input resistance, depressed burst and tonic firing, especially in ventrobasal and intralaminar neurons, while at the same time increasing burst duration and mean conductance at individual chloride channels; this increased both the amplitude and decay time of inhibitory postsynaptic currents.
Amobarbital has been used in a study to inhibit mitochondrial electron transport in the rat heart.
A 1988 study found that amobarbital increases benzodiazepine receptor binding in vivo with less potency than secobarbital and pentobarbital (in descending order), but greater than phenobarbital and barbital (in descending order).
- When given slowly by an intravenous route, sodium amobarbital has a reputation for acting as a so-called truth serum. A person under the influence of the drug in this circumstance will relate information that he or she would otherwise "block." As such, the drug was first employed clinically by Dr. William Bleckwenn at the University of Wisconsin to circumvent inhibitions in psychiatric patients.
- The drug may be used intravenously to interview patients with catatonic mutism, sometimes combined with caffeine to prevent sleep.
- It was used by the United States armed forces during World War II in an attempt to treat shell shock and return soldiers to the front-line duties.
The following drugs should be avoided when taking amobarbital:
- Caffeine
- Benzodiazepines, such as diazepam, clonazepam or nitrazepam
- Antiepileptics, such as phenobarbital or carbamazepine
- Antihistamines, such as doxylamine and clemastine
- Narcotic analgesics, such as morphine and oxycodone
- Steroids, such as prednisone and cortisone
- Antihypertensives, such as atenolol and propranolol
- Antiarrhythmics, such as verapamil and digoxin
Amobarbital has been known to decrease the effects of hormonal birth control, sometimes to the point of uselessness. Being chemically related to phenobarbital, it might also do the same thing to digitoxin, a cardiac glycoside.
Some side effects of overdose include confusion (severe); decrease in or loss of reflexes; drowsiness (severe); fever; irritability (continuing); low body temperature; poor judgment; shortness of breath or slow or troubled breathing; slow heartbeat; slurred speech; staggering; trouble in sleeping; unusual movements of the eyes; weakness (severe).
Amobarbital (5-ethyl-5-isoamylbarbituric acid), like all barbiturates, is synthesized by reacting malonic acid derivatives with urea derivatives. In particular, in order to make amobarbital, α-ethyl-α-isoamylmalonic ester is reacted with urea (in the presence of sodium ethoxide).
- GB patent 191008, Layraud, E., "The manufacture of unsymmetrical c.c.-dialkylbarbituric acids", issued 1923-10-25
- US patent 1856792, Shonle, H. A., "Anhydrous alkali salts of 5,5-di-aliphatic-substituted barbituric acids and processes of producing them", issued 1932-05-03
It has been used to convict alleged murderers such as Andres English-Howard, who strangled his girlfriend to death but claimed innocence. He was surreptitiously administered the drug by his lawyer, and under the influence of it he revealed why he strangled her and under what circumstances. A year later he confessed on the witness stand and was convicted on the basis of these statements. He later committed suicide in his cell.
See also 
References and end notes 
- Kim, H. -S.; Wan, X.; Mathers, D. A.; Puil, E. (2004). "Selective GABA-receptor actions of amobarbital on thalamic neurons". British Journal of Pharmacology 143 (4): 485–494. doi:10.1038/sj.bjp.0705974. PMC 1575418. PMID 15381635.
- Stewart, S.; Lesnefsky, E. J.; Chen, Q. (2009). "Reversible blockade of electron transport with amobarbital at the onset of reperfusion attenuates cardiac injury". Translational Research 153 (5): 224–231. doi:10.1016/j.trsl.2009.02.003. PMID 19375683.
- Miller, L. G.; Deutsch, S. I.; Greenblatt, D. J.; Paul, S. M.; Shader, R. I. (1988). "Acute barbiturate administration increases benzodiazepine receptor binding in vivo". Psychopharmacology 96 (3): 385–390. doi:10.1007/BF00216067. PMID 2906155.
- Maynert, E. W. (1965). "The alcoholic metabolites of pentobarbital and amobarbital in man". The Journal of Pharmacology and Experimental Therapeutics 150 (1): 118–121. PMID 5855308.
- Tang, B. K.; Kalow, W.; Grey, A. A. (1978). "Amobarbital metabolism in man: N-glucoside formation". Research communications in chemical pathology and pharmacology 21 (1): 45–53. PMID 684279.
- Soine, P. J.; Soine, W. H. (1987). "High-performance liquid chromatographic determination of the diastereomers of 1-(beta-D-glucopyranosyl)amobarbital in urine". Journal of chromatography 422: 309–314. doi:10.1016/0378-4347(87)80468-1. PMID 3437019.
- Bleckwenn, W. J. (1930). "Sodium amytal in certain nervous and mental conditions". Wisconsin Medical Journal 29: 693–696.
- Stocks, J. T. (1998). "Recovered memory therapy: A dubious practice technique". Social work 43 (5): 423–436. doi:10.1093/sw/43.5.423. PMID 9739631.
- McCall, W. V. (1992). "The addition of intravenous caffeine during an amobarbital interview". Journal of psychiatry & neuroscience : JPN 17 (5): 195–197. PMC 1188455. PMID 1489761.
- "Use of sodium amytal during WWII". Battle of the Bulge - program transcipt. pbs.org. "Ben Kimmelman, Captain, 28th Infantry: The assumptions were that this would have some kind of cathartic effect, the sodium amytal, which the men called blue 88's. You know, the most effective artillery piece of the Germans was the 88 and this was blue 88's, because the sodium amytal was a blue tablet."
- Rebecca Leung (February 11, 2009). "Truth Serum: A Possible Weapon". 60 Minutes. CBS News.