Barbiturates

Overview

Barbiturates are substances that act as depressants on the central nervous system. In low doses barbiturates have a sedative or tranquilizing effect. Increased doses can induce sleep. Still higher doses can act as anticonvulsant or anesthetic.

All barbiturates act in the same way, only differing at the speed with which they do it and the duration of their effects on the body. There are ultra-short-acting barbiturates that are used in surgery; short and intermediate-acting barbiturates that induce sleep; and long-acting ones that are the most widely-used for pain relief, for the control of migraine and other severe headaches and for the treatment of epilepsy.

Under United States law, barbiturates are controlled substances. They can have adverse side effects when used in very high doses, and can be addictive when used for extended periods. This dependency and its adverse effects will be discussed further down.

Screening Cut-off and Detection Time

In drug screening, the cut-off level is that point which separates a negative and a positive test result. Screening cut-off levels are established where drug detection is optimized with the least probability for false positives. It is important to remember that a negative sample does not necessarily mean that it is drug-free, only that it contains a drug at a concentration that is below the established cut-off.

For barbiturates, this cut-off level is at 300 ng/ml within a detection period of 2-4 hrs up to 1-3 weeks.

Another important point to remember is that if a barbiturate test is screen positive, it merely proves the presence of the drug in the sample, not how much of it was taken or how impaired the person was. A presumptive positive test therefore requires a confirmation test.3

DEA Drug Class

The Drug Enforcement Administration implements the Controlled Substance Act and sees to the prosecution of violators. The CSA is the U.S. drug policy that regulates the use, possession, distribution, manufacture and importation of certain narcotics, depressants, stimulants, hallucinogens, anabolic steroids and other chemicals. The CSA defines 5 schedules of drug classification (I–V) based on their abuse potential, safety and medical applications.4

Barbiturates fall under Schedule III – drugs and other substances that: have less potential for abuse compared to Schedules I and II; are currently accepted in the United States for use in medical treatment; and those, the abuse of which may lead to moderate to low physical dependence or high psychological dependence.5

Drug Type

Barbiturates are depressants. Depressants are drugs that slow down the central nervous system, giving one a general feeling of relaxation, causing temporary relief from stress and anger.6 These types of drugs are often used as sleeping pills and sedatives.

Forms and Routes of Administration

Barbiturates can be administered in a variety of ways and come in different forms, namely:

  • Capsule – Barbiturates are commonly found in powder form contained and sold in brightly-colored capsules for oral ingestion.
  • Elixir – By definition, an elixir is a clear, sweetened hydro-alcoholic liquid used as a vehicle for the active ingredient it contains. Conversely, a barbiturate elixir is a liquid form of the drug intended for oral ingestion.7
  • Enema – Enemas are mainly used for cleansing or purgation and pre-operative sedation in relatively small-dose volumes.8
  • Solution – In pharmacology, a solution is a liquid preparation of one or more soluble chemical substances, usually dissolved in water.9 Barbiturate solutions are prepared for either oral ingestion or injection.
  • Suppository – This form of barbiturates is prescribed for patients who have been on oral barbiturates but have shown emotional instability and suicidal tendencies. The use of barbiturates in the form of rectal suppositories considerably reduces the potential for abuse because of delayed gastrointestinal absorption.10
  • Suspension – In a suspension, the active ingredient is mixed with a liquid, usually water, but is not dissolved. It remains intact in its original form of small particles. Before dispensing a dose, a solution is supposed to be shaken in order to evenly distribute the active ingredient throughout the liquid.
  • Tablet – This is one of the most common forms for barbiturates, usually prescribed as sleeping pills.

Brand Names

  • Alurate
  • Amytal
  • Brevital
  • Butisol
  • Fioricet
  • Fiorinal
  • Lotusate
  • Luminal
  • Mebaral
  • Nembutal
  • Pentothal
  • Phanodorm
  • Prominal
  • Seconal
  • Soneryl
  • Surital
  • Vesparax

Uses of Barbiturate

The very first uses for barbiturates have been for sedation and the inducement of sleep until they discovered that it was also an effective treatment for epileptic seizures. Over the years barbiturates have found their way into a few other applications depending on the dose and how fast-acting they are.

Ultrashort-acting barbiturates

The ultrashort-acting barbiturates are given before surgery to induce anesthesia, or the temporary state that includes one or more of the following:

Examples of barbiturates used for this application are thiamylal (Surital), methohexital (Brevital) and thiopental (Pentothal). These drugs are administered under controlled hospital settings.

Short-acting and intermediate-acting barbiturates

Barbiturates under this category are prescribed as sleeping pills and sedatives for humans. For animals, vets use pentobarbital to induce anesthesia or to put suffering animals to sleep. Examples of short-acting and intermediate-acting barbiturates include secobarbital (Amatyl, Seconal), pentobarbital (Nembutal), bubalbital (Fioricet, Florinal), talbutal (Lotusate), aprobarbital (Alurate), butabarbital (Butisol) and a mix of secobarbital and amobarbital (Tuinal).

Additionally, secobarbital and pentobarbital are the most commonly used barbiturate for physician-assisted suicides.11

Long-acting barbiturates

Long-acting barbiturates are used to help patients sleep. They are also used for day-long sedation for people being treated for anxiety. When used with other drugs, long-acting barbiturates are used to control the pain from migraine headaches and to treat convulsive disorders like epilepsy. The oldest drug in this category is Phenobarbital.

There is one other interesting use for barbiturates in the field of psychology, law enforcement and the military. This application involves sodium pentothal in particular, more popularly known as the “truth serum”. This drug allows access to the levels of human consciousness that are normally only tapped in dream or trance state. The drug is therefore used on traumatized WW2 soldiers during therapy. Under the influence of sodium pentothal, these soldiers are able to relive and better verbalize their battle experiences buried deep enough by voluntary recollection. The drug also takes away a person’s normal levels of inhibition, making them more forthcoming with information that they would otherwise withhold. It is thus used by law enforcement on prisoners and other crime suspects under investigation.12

Street Names

  • Barbs
  • Blockbusters
  • blue devils
  • blue birds
  • blues
  • christmas trees
  • downers
  • goof balls
  • phennies
  • phenobarbital
  • pinks
  • rainbows
  • red birds
  • red devils
  • reds & blues
  • reds
  • sekkies
  • sleepers
  • sleeping pills
  • tooies
  • tuninal
  • yellow jackets

Effects and Symptoms

It is best for people who take barbiturates to see their doctors regularly to ensure that the drug is working as it should while watching out for unwanted side effects. This is especially important if there are other medications involved, like if a person is taking antihistamines, cold medicines, muscle relaxants, OTC pain relievers or if a person is drinking alcohol. The combined effects of barbiturates and these other drugs and substances on the central nervous system can be very dangerous and may lead to unconscious or even death. Anyone who experiences symptoms of an adverse reaction to barbiturates or a possible overdose should seek emergency medical assistance immediately. These symptoms include:

  • breathing problems
  • severe confusion
  • severe drowsiness
  • severe weakness
  • slow heartbeat
  • slurred speech
  • staggering

People who take barbiturates are advised not to drive or operate machinery because of these side effects.

Special Conditions

Children are especially sensitive to these drugs, increasing the chances of side effects like unusual and heightened excitability. For older people and those who are very ill, barbiturates can cause depression, confusion and unusual excitement.

The results of certain medical tests may also be affected by barbiturates, so it is important for people who take them to inform the attending health care professional before any tests are performed.

People with certain medical conditions are at higher risk from complications due to barbiturates especially as it is very likely that they are taking some medications to address their issues. Again, attending physicians should be made aware of these medical conditions if they are writing out prescriptions for barbiturates.

  • Pregnancy – Barbiturates increase the risk of prolonged labor and birth defects. The newborn may also suffer from the effects of withdrawal. If a pregnant woman is ever faced with the decision to take barbiturates due to certain serious or life-threatening conditions, she must be made aware of all the benefits and risks involved in order to make an informed decision.
  • Breastfeeding – Nursing babies may suffer from slow heartbeat, breathing problems and drowsiness from barbiturates taken by their mother. Nursing mothers should first consult with their physician before taking barbiturates.
  • Allergies – Past allergies to barbiturates and other allergens should be pointed out to a prescribing physician if a new prescription is to be written out.

The following medical conditions should also be made known to an attending physician if barbiturates are to be prescribed for a patient:

  • alcohol or drug abuse
  • asthma
  • chronic pain
  • depression
  • diabetes
  • emphysema
  • hyperactivity (in children)
  • hyperthyroidism
  • hypoadrenalism
  • kidney disease
  • liver disease
  • porphyria
  • severe anemia

Dependence

When a person begins craving barbiturate, it is the beginning of dependence to the drug. Dependence is either psychological or physical.

Psychological dependence or addiction begins when a person feels overwhelmed or unable to cope with normal life without the drug. Whenever feelings of anxiety, stress or loneliness become too much and the only way to relieve these feelings is to take the drug, that is psychological dependence.

Physical dependence is characterized by a compelling craving for the drug and by withdrawal symptoms when the drug use stops.

When a person begins to need larger or more frequent doses of barbiturates in order to achieve the same effects, that person is very likely beginning to develop barbiturate tolerance.

Barbiturates are highly addictive. The habit develops innocently enough when people start taking barbiturates for legitimate therapeutic reasons like managing anxiety or treating insomnia. The problem often begins when left-over pills from a previous prescription are left lying around in the house where other family members or visitors help themselves to the pills without fully understanding the consequences of taking them.

History

The history of barbiturates is as bizarre as its effects and its significance in society over the years. It was founded by German chemist Adolf von Baeyer. It is said that on St. Barbara’s day in 1864, he developed a compound from urea and malonic acid (a chemical found in apples). He called this new compound barbituric acid, in honor of St. Barbara.

In those days the only way for chemists to test their discovered compounds was to taste said compounds themselves or have their employees do the tasting and wait for observable signs of any therapeutic significance. At the time, they found none.1

It wasn’t until 1903 that the first medicinal use for barbiturate was discovered by Emil Fischer and Joseph von Mering. They discovered that barbital was an effective sleep inducer for dogs. It was a great commercial opportunity that pharmaceutical company Bayer (no connection to Adolf von Baeyer) immediately recognized, and they began manufacturing under the brand Veronal, named after the “most peaceful town” known to von Mering. Veronal became widely used for its sedative and hypnotic effects. Back then, drugs that induce sleep were generally referred to as hypnotic drugs.

Phenobarbital was first synthesized in 1911 by Hörlein and the following year it was marketed by Bayer as Luminal. In 1912, when a young clinical assistant by the name of Alfred Hauptmann began giving phenobarbital to epileptic patients to help them sleep, he observed that their night time seizures (which disturbed his own sleep and was actually the reason he began using Luminal on said patients) appeared to have been suppressed as well. This serendipitous finding drove him to systematically study the drug’s potential as an anti-epileptic.

Back then it was possible for newly developed drugs to be introduced into practice quite rapidly. Barbiturates in general have became so successful that by 1960 over 2500 barbiturate derivatives had been synthesized and used for clinical practice as sedatives, hypnotics, anesthetics, anti-epileptics and anxiolytics.2