Amytal n : the sodium salt of amobarbital that is used as a barbiturate; used as a sedative and a hypnotic [syn: amobarbital sodium, blue, blue angel, blue devil]

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.

Pharmacology

According to an in vitro study conducted at the University of British Columbia, amobarbital works by activating GABAA 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.

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

Metabolism

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

Indications

Approved

• Anxiety
• Insomnia
• Epilepsy

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 alleged murderers such as Andres English-Howard, who strangled his girlfriend to death but claimed innocence. He was surreptitiously administered the drug, by his attorney, and under the influence of it he revealed why he strangled her and under which circumstances. A year later he confessed, on the stand, and was convicted on the basis of these statements; he later committed suicide in his cell. The use of amobarbital as a truth serum has lost credibility due to the discovery that the subject can be coerced into having a 'false memory' of the event. In controlled doses, it is used in the Narco Analysis test to trace crime and criminals in modern forensics.

• Catatonic mutism, sometimes combined with caffeine to combat somnolence.

• It was also used in the Battle of the Bulge as a healing pill to send people back to the front.

Contraindications

The following drugs should be avoided when taking amobarbital:

• Alcohol
• Caffeine
• 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
• 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).

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). Death can be a result.

See also

• Depressants
• Barbiturates
• Wada test

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.

External links