Amobarbital

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Amobarbital
Systematic (IUPAC) name
5-ethyl-5-(3-methylbutyl)-1,3-diazinane-2,4,6-trione
Identifiers
CAS number	57-43-2 64-43-7 (sodium salt)
ATC code	N05CA02
PubChem	2164
DrugBank	none
Chemical data
Formula	C11H18N2O3
Mol. weight	226.272
Pharmacokinetic data
Bioavailability	?
Metabolism	Hepatic
Half life	8-42 hours
Excretion	Renal
Therapeutic considerations
Pregnancy cat.	?
Legal status	Schedule IV(CA) Schedule II/Schedule III (US)
Routes	Oral, IM, IV, Rectal

Amobarbital (formerly known as amylobarbitone) is a drug that is a barbiturate derivative. It has sedative-hypnotic and analgesic properties. It is a white crystalline powder with no odor and a slightly bitter taste. If amobarbital is taken for extended periods of time, physical and psychological dependence can develop.

Contents 1 Pharmacology 1.1 Metabolism 2 Indications 2.1 Approved 2.2 Unapproved/Off-Label 3 Contraindications 4 Overdose 5 See also 6 References and End Notes 7 External links

[edit] Pharmacology

According to an in vitro study conducted at the University of British Columbia, amobarbital works by activating GABA_A receptors, which decreases input resistance, depresses 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 increases both the amplitude and decay time of inhibitory postsynaptic currents.^[1]

It has an LD50 in mice of 212 mg/kg s.c.

[edit] Metabolism

Amobarbital undergoes both hydroxylation to form 3'-hydroxyamobarbital^[2], which has both levorotatory and dextrorotatory isomers^[3] and N-glucosidation^[4] to form 1-(beta-D-glucopyranosyl)amobarbital.^[5]

[edit] Indications

[edit] Approved

• Anxiety
• Insomnia
• Epilepsy
• Catatonic mutism, sometimes combined with caffeine to combat somnolence.^[6]

[edit] Unapproved/Off-Label

Sodium amobarbital has a reputation for having activity as a truth serum, where the person under the influence of the drug will submit to almost any request given by another person. It has been used to convict murderers such as Andres English-Howard, who strangled his girlfriend to death but pleaded innocent. He had surreptitiously been administered the drug, under the influence of which he revealed why he strangled her and under which circumstances. He was convicted on the basis of these statements, and committed suicide in his cell^[7]. This use has lost credibility due to the discovery that the patient can sometimes be made to have 'memories' of events that never happened.

[edit] Contraindications

The following drugs should be avoided when taking amobarbital:

• Alcohol
• Caffeine^{[citation needed]}
• Chloramphenicol
• Chlorpromazine
• Cyclophosphamide
• Ciclosporin
• Digitoxin
• Doxorubicin
• Doxycycline
• Methoxyflurane
• Metronidazole
• Quinine
• Theophylline
• Warfarin
• 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
• Antidepressants ^{[citation needed]}
• 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.

In 1988, Miller et al reported 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 ascending order).^[8]

[edit] Overdose

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).

[edit] See also

• Depressants
• Barbituates
• Wada test

[edit] References and End Notes

1. Controlled Substances in Schedule II Office of Diversion Control, Drug Enforcement Administration.
2. Controlled Substances in Schedule III Office of Diversion Control, Drug Enforcement Administration.
3. ↑  Kim HS, Wan X, Mathers DA, Puil E. "Selective GABA-receptor actions of amobarbital on thalamic neurons." British Journal of Pharmacology. 2004 Oct;143(4):485-94. Epub 2004 Sep 20. PMID 15381635 Fulltext
4. ↑  Maynert EW. "The alcoholic metabolites of pentobarbital and amobarbital in man." Journal of Pharmacology and Experimental Therapeutics. 1965 Oct;150(1):118-21. PMID 5855308
5. ↑  Chemicals: 3'-hydroxyamobarbital The Comparative Toxicology Database.
6. ↑  Tang BK, Kalow W, Grey AA. "Amobarbital metabolism in man: N-glucoside formation." Research Communications in Chemical Pathology and Pharmacology. 1978 Jul;21(1):45-53. PMID 684279
7. ↑  Soine PJ, Soine WH. "High-performance liquid chromatographic determination of the diastereomers of 1-(beta-D-glucopyranosyl)amobarbital in urine." Journal of Chromatography. 1987 Nov 27;422:309-14. PMID 3437019
8. ↑  McCall WV. "The addition of intravenous caffeine during an amobarbital interview." Journal of Psychiatry & Neuroscience. 1992 Nov;17(5):195-7. PMID 1489761
9. ↑  Truth Serum: A Possible Weapon, 60 minutes, April 23, 2003.
10. ↑  Miller LG, Deutsch SI, Greenblatt DJ, Paul SM, Shader RI (1988). "Acute barbiturate administration increases benzodiazepine receptor binding in vivo". Psychopharmacology (Berl) 96 (3): 385-90. PMID 2906155

[edit] External links

• Links to external chemical sources.

Barbiturates edit
Allobarbital, Amobarbital, Aprobarbital, Barbexaclone, Barbital, Butabarbital, Butalbital, Butobarbital, Cyclobarbital, Ethallobarbital, Heptabarbital, Hexobarbital, Mephobarbital, Metharbital, Methohexital, Methylphenobarbital, Pentobarbital, Phenobarbital, Primidone, Proxibarbal, Reposal, Secobarbital, Talbutal, Thiobarbital, Thiopental, Vinbarbital, Vinylbital