Scientific Name: The pharmacologically active barbiturates are all based on the use of barbituric acid as the skeleton chemical makeup. The IUPAC name is 2,4,6-(1H,3H,5H)-pyrimidinetrione, and different drugs have various elements which are most often at the 5 position. There are many different barbiturate drugs that have been produced over the years.

Other Common Names: The many common street names include barbs, blue heavens, downers, blues, F 40s, blockers, Mexican Reds, nimby, phennies, pinks, reds, reds and blues, red devils, blockbusters, rainbows, sleepers, tooies, yellow jackets, and yellows, and many more.

Description: Barbiturates are in a class of drugs called sedative-hypnotics or Central Nervous System (CNS) depressants. They work on the chief inhibitory neurotransmitter in the Central Nervous System, which is one reason they are so potent. Barbiturates are used to treat insomnia, anxiety, and seizure disorders, and to cause drowsiness or unconsciousness such as in preparation for surgery.

Barbiturates are not prescribed by physicians much anymore because they have been replaced with drugs like tranquilisers that present a lower risk of overdose and physical dependence. That has led to barbiturates becoming an uncommon drug of abuse in Australia. They are mostly used today for the treatment of epilepsy, and other medical conditions marked by convulsions, and for anaesthesia.

Source: Each barbiturate is a derivative of barbituric acid that is chemically manufactured as a medically active drug.

Forms: Barbiturates have been manufactured in many forms, including as tablet, capsule, liquid, injectable, elixir, and suppository. Most of the time the drug is administered orally or by injection.

Health Effects

Psychological Effects: Barbiturates cause drowsiness, poor concentration, dizziness, confusion, sedation, euphoria, irritability, impaired judgment, and decreased anxiety. People taking barbiturates sometimes act similar to a person who is intoxicated.

Physical Effects:

Acute – The short-term effects of barbiturates last approximately 15 to 22 hours. They include relief of anxiety, lowered blood pressure, respiratory depression, slurred speech, memory impairment, sleepiness, feeling intoxicated, and difficulty walking or remaining balanced. Some people develop headaches, memory problems, and gastrointestinal issues.

Long-term – The long-term effects of barbiturates include slowed reflexes, chronic tiredness, vision problems, lack of coordination, breathing disorders (from respiratory depression), dizziness, menstrual irregularities, and sexual dysfunction.

Regular use of barbiturates is likely to lead to rapid drug tolerance and addiction. Once drug tolerance develops, it can take as much as 10 times the original amount of the drug to produce the same effects. Barbiturates have a high potential for overdose leading to death because tolerance to the drug increases but the lethal dose amount does not. This increases the risk of barbiturate poisoning as users take more and more of the drug. The drug also becomes even more lethal when mixed with other CNS depressants like alcohol, benzodiazepines, and opiates. All of these chemicals act on the same brain receptors, so the effects are multiplied. They should also not be mixed with cold medicines, pain relievers, muscle relaxants, and antihistamines.

Symptoms of overdose include respiratory distress, drowsiness, slurred speech, hypothermia, hypotension, respiratory arrest, and death. When there is a delayed death due to a barbiturate overdose, the death is often due to something like multi-organ system failure or cerebral edema (fluid collection.)

Abrupt withdrawal from barbiturates is dangerous because it can be life-threatening. Withdrawal symptoms include nausea, vomiting, abdominal cramps, sweating, anxiousness, weakness, elevated blood pressure, fast pulse, muscle pain, and restlessness. These symptoms may last 2-3 days. At that point, most people who are addicted to barbiturates will experience seizures, convulsions, and/or delirium similar to alcohol withdrawal symptoms. Delirium may include hallucinations. Total withdrawal is usually completed within 8 days.

Detection Period: Barbiturates are classified as ultra-short, short, intermediate, and long acting, indicating how quickly they act in the body and the duration of action in the body. The ultra-short is the type used to produce rapid unconsciousness for something like surgery. This form of barbiturate is seldom abused because it is so carefully controlled in the hospital setting. The short acting barbiturates like pentobarbital are detectable for up to 4 days. The long acting barbiturates like phenobarbital are detectable for up to 30 days. The Standards Australia AS/NZS 4308 sets the cutoff level for barbiturates in urine as .0.2 ug/ml.

Legal Status: Barbiturates are legal if prescribed by a doctor and used in accordance with the physician’s instructions. They are Schedule 4 – Prescription Only Medicines per the Standard for the Uniform Scheduling of Medicines and Poisons.

Other Information: Pentobarbital, the short acting barbiturate, is sold under names like Nembutal and Sedalphorte. An interest among some people in promoting euthanasia has led to an increase in the attempted illegal import of Nembutal for assisted suicide, bringing barbiturates back into the limelight. Only a physician can apply for the import of barbiturates through the Special Access Scheme which is administered by the Therapeutic Goods Administration.


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