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Death may occur when barbiturates are combined with depressants such as opiates, benzodiazepines, gabapentinoids, thienodiazepines, alcohol or other GABAergic substances.[1]

It is strongly discouraged to consume moderate to heavy dosages of these substances together.

Not to be confused with Amobarbital.
Summary sheet: Amobarbital
Chemical Nomenclature
Common names Amobarbital, amylobarbitone
Substitutive name sodium amytal
Systematic name 5-ethyl-5-(3-methylbutyl)-1,3-diazinane-2,4,6-trione
Class Membership
Psychoactive class Depressant
Chemical class Barbiturate
Routes of Administration

WARNING: Always start with lower doses due to differences between individual body weight, tolerance, metabolism, and personal sensitivity. See responsible use section.

DISCLAIMER: PW's dosage information is gathered from users and resources for educational purposes only. It is not a recommendation and should be verified with other sources for accuracy.


Amobarbital (formerly known as amylobarbitone or sodium amytal as the soluble sodium salt) 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. It is considered a short to intermediate acting barbiturate.[citation needed] If amobarbital is taken for extended periods of time, physiological and psychological dependence can develop.

Amobarbital withdrawal mimics delirium tremens and may be life-threatening. Amobarbital was manufactured by Eli Lilly and Company in the US under the brand name Amytal in bright blue bullet shaped capsules (known as Pulvules) or pink tablets (known as Diskets) containing 50, 100, or 200 milligrams of the drug. The drug was also manufactured generically. Amobarbital was widely misused, known as Blue Heavens on the street. Amytal, as well as Tuinal, a combination drug containing equal quantities of secobarbital and amobarbital, were both manufactured by Eli Lilly until the late-1990s. However, as the popularity of benzodiazepines increased, prescriptions for these medications became increasingly rare beginning in the mid to late-1980s.


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).


In an in vitro study in fat 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.[2]

Amobarbital has been used in a study to inhibit mitochondrial electron transport in the rat heart in an attempt to preserve mitochondrial function following reperfusion.[3]

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).[4] (Secobarbital > pentobarbital > amobarbital > phenobarbital > barbital)

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

Subjective effects

Disclaimer: The effects listed below cite the Subjective Effect Index (SEI), an open research literature based on anecdotal user reports and the personal analyses of PsychonautWiki contributors. As a result, they should be viewed with a healthy degree of skepticism.

It is also worth noting that these effects will not necessarily occur in a predictable or reliable manner, although higher doses are more liable to induce the full spectrum of effects. Likewise, adverse effects become increasingly likely with higher doses and may include addiction, severe injury, or death ☠.

Physical effects

Visual effects

Cognitive effects

Experience reports

There are currently no anecdotal reports which describe the effects of this compound within our experience index. Additional experience reports can be found here:

Toxicity and harm potential

Radar plot showing relative physical harm, social harm, and dependence of barbiturates in comparison to other drugs.[3]

Amobarbital likely has moderate toxicity relative to dose. However, amobarbital is potentially lethal when mixed with depressants like alcohol or opioids. Phenobarbital has a higher risk of death or serious adverse effects associated with concurrent depressant use than other drugs such as benzodiazepines.

It is strongly recommended that one use harm reduction practices when using this drug.

Lethal dosage

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

Tolerance and addiction potential

Amobarbital is extremely physically and psychologically addictive. Barbiturate withdrawal is medically serious and can potentially cause a life-threatening withdrawal syndrome that can cause seizures, psychosis, and death. Drugs which lower the seizure threshold such as tramadol and amphetamine should be avoided during withdrawal.

Tolerance will develop to the sedative-hypnotic effects of amobarbital after prolonged use. It is unknown exactly how long it takes for tolerance to reach baseline. Amobarbital presents cross-tolerance with all barbiturates, meaning that after its consumption all barbiturates will have a reduced effect.

Dangerous interactions

Although many drugs are safe on their own, they can become dangerous and even life-threatening when combined with other substances. The list below contains some common potentially dangerous combinations, but may not include all of them. Certain combinations may be harmless in low doses of each but still increase the potential risk of death. Independent research should always be done to ensure that a combination of two or more substances is safe before consumption.

  • Depressants (1,4-Butanediol, 2-methyl-2-butanol, alcohol, barbiturates, GHB/GBL, methaqualone, opioids) - This combination can result in dangerous or even fatal levels of respiratory depression. These substances potentiate the muscle relaxation, sedation and amnesia caused by one another and can lead to unexpected loss of consciousness at high doses. There is also an increased risk of vomiting during unconsciousness and death from the resulting suffocation. If this occurs, users should try to fall asleep in the recovery position or have a friend move them into it.
  • Dissociatives - This combination can lead to an increased risk of vomiting during unconsciousness and death from the resulting suffocation. If this occurs, users should attempt to fall asleep in the recovery position or have a friend move them into it.
  • Stimulants - It is unsafe to combine barbiturates with stimulants due to the risk of excessive intoxication. Stimulants decrease the sedative effect of barbiturates, which is the main factor most people consider when determining their level of intoxication. Once the stimulant wears off, the effects of barbiturates will be considerably increased, leading to intensified disinhibition as well as other effects. If combined, one should strictly limit themselves to only dosing a certain amount of barbiturates per hour. This combination can also potentially result in severe dehydration if hydration is not monitored.


Barbiturate overdose may occur when a barbiturate is taken in extremely heavy quantities or concurrently with other depressants. This is particularly dangerous with other GABAergic depressants such as benzodiazepines and alcohol since they work in a similar fashion, but bind to distinct allosteric sites on the GABAA receptor, thus their effects potentiate one another. Benzodiazepines increase the frequency in which the chlorine ion pore opens on the GABAA receptor while barbiturates increase the duration in which they are open, meaning when both are consumed, the ion pore will open more frequently and stay open longer[4]. Barbiturate overdose is a medical emergency that may lead to a coma, permanent brain injury or death if not treated promptly and properly. Barbiturate overdose has an increased frequency of serious adverse effects when compared to other depressants.

Symptoms of a barbiturate overdose may include severe thought deceleration, slurred speech, confusion, delusions, respiratory depression, coma or death[5].

Legal status

Internationally, amobarbital is listed in Schedule IV of the UN Convention on Psychotropic Substances.[6]

See also

External links


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