Phenobarbital Addiction, Abuse and Use

Last Updated: October 22, 2021

Authored by Roger Weiss, MD

Reviewed by Michael Espelin APRN

Phenobarbital is among the class of drugs known as barbiturates. It, along with other barbiturates, are all types of sedative-hypnotic drugs that have a broad array of use that ranges from the treatment of seizures, alcohol withdrawal, insomnia, and preoperative anxiety, to the induction of anesthesia and even clinical coma. However, in recent years barbiturates have lost their once prominent role in health care and have largely been replaced by either benzodiazepines, Z drugs, or other substances. This shift was the result of a lower safety profile of barbiturates in both clinical use and instances of overdose when compared to other sedative hypnotics. As well as a higher tendency for abuse and dependency with barbiturate use.

Regardless, certain barbiturates such as Phenobarbital are still in use today for their effectiveness in niche medical scenarios. Therefore, this article will endeavor to provide an overview of various Phenobarbital uses and dosages, its pharmacological classification, as well as information on what causes and how to deal with instances of Phenobarbital abuse and Phenobarbital addiction.

A man holds Phenobarbital pills and a glass of water.

What Is Phenobarbital?

Phenobarbital is a sedative-hypnotic belonging to the class of barbiturates. Its sedative-hypnotic properties are employed in medical care settings for anti-seizure management, treatment for status epilepticus, insomnia, as well as method of treatment to help with benzodiazepine and alcohol withdrawal. Below, will be discussed the pharmacologic phenobarbital classification as well as phenobarbital schedule under the Controlled Substances Act of the United States Drug Enforcement Agency (DEA).

Phenobarbital Classification

As mentioned before, Phenobarbital belongs to the barbiturate class of drugs. The first barbiturate was synthesized in Germany in 1864, and was called barbituric acid. Barbituric acid was unfortunately not lipophilic. As such, it was unable to cross the blood brain barrier and as a result lacked innate central nervous system effects. However, over the next century chemical modification of this substance yielded the group of barbiturates we know today.

Phenobarbital is one such modification and belongs to the subgroup of oxybarbiturates. The “oxy” in their name implies that within its chemical structure, it has an oxygen atom attached to its second carbon(C2). This property makes this medication less lipid soluble when compared to other barbiturate congeners such as Thiopental or Methohexital.

This Lower Lipid Solubility Alters the Pharmacokinetic and Pharmacodynamic Properties of This Drug and Yields the Following Changes:

  • Longer duration of action
  • Increased latency to onset of activity
  • Decreased metabolic degradation
  • Decreased hypnotic potency when compared to more lipid soluble barbiturates

And lastly, Phenobarbital, due to its mechanism of action saw much use as a sedative-hypnotic during the late 1800s and early 1900s, and then by mere chance its anti-seizure properties were discovered by a young doctor, Alfred Hauptmann, working with epileptic patients in Freiburg, Germany. Since then, it became a frequently prescribed drug for its sedative-hypnotic and anti-seizures properties well into the 1960s.

Is Phenobarbital A Controlled Drug?

Now with regard to Phenobarbital schedule, under the Controlled Substances Act of 1970 it is schedule IV controlled substance classified and regulated by the United States Drug Enforcement Administration (DEA). The United States Drug Enforcement Administration added this drug to this schedule because of a moderate potential for Phenobarbital abuse which can lead to dependence and Phenobarbital addiction.

What Is Phenobarbital Used For?

The list of potential Phenobarbital uses are quite varied, giving this medication significant therapeutic applications. And this was the case until the latter half of the 20th century when its use in clinical care settings was replaced by safer drugs such as benzodiazepines. However, Phenobarbital uses in certain clinical settings have remained unchanged. Some of these indications for use include anti-seizure management especially in certain pediatric populations with epilepsy, treatment for status epilepticus, daytime insomnia, as well as a treatment to help alleviate the symptoms of benzodiazepine and alcohol withdrawal.

Below Are Discussed in More Detail Some of These Uses:

Seizures Phenobarbital has been used for the treatment of seizures since the 1920s. It can be used to treat a variety of seizures and epilepsy syndromes that include:

  • Lennox-Gastaut Syndrome
  • Rasmussen’s Syndrome
  • Temporal Lobe Epilepsy
  • Clonic Seizures
  • Complex Partial Seizures
  • Refractory Seizures/Status Epilepticus
  • Secondarily Generalized Seizures
  • Bilateral Tonic Clonic Seizure
  • Simple Partial Seizure
  • Tonic Seizures
  • Tonic-clonic Seizures

Although it has a long history of use and is quite effective, it also has quite an extensive adverse effect profile and its discontinuation can be quite dangerous if done improperly. For these and other reasons the use of this medication for seizures and other epilepsy syndromes has largely been replaced with other, more safe alternatives which have more tolerable side effects.

Anxiety Phenobarbital use originally was as a sedative. While it can be used for short-term sedation, such as for emergency treatment, in surgery, or to calm someone who has a psychiatric episode, it is most famous as a long-term sedative for individuals in intensive care. This is because it is longer acting than many other tranquilizers, allowing caregivers to give less medication to the patient.
Alcohol and Benzodiazepine Withdrawal Another application is in the recovery from alcohol and benzodiazepine withdrawal. In this case, it is used to sedate the patient so that they either do not experience delirium tremens, or so that their experience of it is lessened during their recovery period. The patient is given the medication as often as needed to keep them at the desired level of sedation. It is common to use barbiturates for this application, and phenobarb has proven to be better than most in its drug class for this use. However, it is not yet clear if using phenobarbital for alleviating the symptoms of  withdrawal can harm the individual’s long term recovery from addiction.

Phenobarbital can be quite habit-forming, causing physical and psychological dependence, as well as tolerance, which has a potential for causing overdose. These factors are even more prevalent when a patient is under prolonged treatment with this drug. Hence, doctors rarely prescribe this medication for more than two weeks.

Phenobarbital Brand Name

There are many phenobarbital brands in today’s pharmaceutical market with various brand labels. Phenobarbital is popularly known by other forenames such as Phenobarb or Phenobarbitone. Since the discovery of the drug in 1912, its vocabulary has continually evolved based on its effects, properties, trend, and others. Brand names may differ from one region to the other. The brand “Luminal” was the first manufacturer right before the introduction of multiple brands. Brand names differ mainly when mixed with multiple ingredients and medications to fulfill various functions.

Here Is A List of Common Brand Names:

  • Luminal or Solfoton
  • Epinil
  • Phenobarbitone Sodium
  • Phonetone
  • Barbinol
  • Gardenal
  • Shinosun
  • Fenobarb
  • Epigard

Phenobarbital Dosage Forms And Strengths

Phenobarbital can be administered through a variety of routes. These routes can include Oral (PO), Intramuscular (IM), and Intravenous (IV).

  • Oral tablets of Phenobarbital come in doses of 15, 30, 60, and 100 milligrams.
  • Intramuscular and Intravenous Phenobarbital is provided in various doses based on the patient’s condition and their age. For example, for the relief of preoperative anxiety in an adult Phenobarbital dosage of 100-200mg of IV or IM can be given 90 minutes before the procedure. Similarly, in a pediatric patient 1-3 mg/kg IM or IV can be used.

Phenobarbital Addiction Overview

Barbiturates including Phenobarbital have a moderate tendency for abuse and addiction. This tendency is related to the rapid development of tolerance to the effects of barbiturates, especially with continued use. This leads to the emergence of both physical and psychological dependence, and in the case of abstinence, severe withdrawal symptoms. Due to these effects, patients often keep taking larger and more frequent amounts of barbiturates in order to achieve the same desired sedative-hypnotic effects and to avoid the development of withdrawal symptoms. This phenomenon is the definition of Phenobarbital abuse leading to the development of Phenobarbital addiction.

Furthermore, this medication is rarely abused alone. It is often abused in conjunction with alcohol and other illicit substances, and if a user’s reach to this medication is restricted they will often use one of the many varieties of medications that can produce similar sedative-hypnotic effects.

Phenobarbital Abuse Statistics

Phenobarbital abuse is more common among mature adults who have long histories of sedative-hypnotic and other substance abuse. When considering this medication among all sedative hypnotic drugs around 6% of individuals have reported illicit use of either sedatives or hypnotics. More recently, in 2018 405,000 and 32,000 Americans aged 12 and up reported using and misusing barbiturates respectively.

Phenobarbital Users Can Be Broken Down Into Two Main Groups:

  • A mild abuser, who may be a middle-aged >45 woman who is a regular user of small prescription doses for its hypnotic effects. This group is psychologically dependent but not physically.
  • A severe abuser, who is most often a young male who uses intravenous barbiturates as well as multiple other drugs.

Who is Most at Risk of Phenobarbital Abuse and Addiction?

Abuse and subsequent addiction can occur in various settings and with various spectrums of barbiturate use. For example, occasional use of a barbiturate hypnotic at night, intermittent use during the day to achieve intoxication, and intravenous use due to physical dependence are all examples of abuse and have the potential to lead to phenobarbital addiction. With regard to who may be at risk for abuse and subsequent addiction the answer is such, there are multiple risk factors that may increase the likelihood that an individual may abuse a sedative hypnotic medication.

These Risk Factors Include:

  • Genes: Family history of substance abuse or addiction
  • Gender: As already mentioned, women are more likely than men to use and abuse sedative hypnotic medications
  • Exposure: Being in an environment where sedative hypnotic use is tolerated and accepted or being in association with those individuals who already abuse sedative-hypnotic medications.
  • Substance Use Disorder: Patients already struggling with dependence on other substances have a higher risk of further substance abuse.
  • Behavioral Traits: Individuals who have predisposition to aggression, impulsivity, and novelty seeking behaviors.

It is important to remember that substance use and abuse is complex and there may be multiple or even a single factor that can drive an individual towards abuse and addiction.

A woman experiences headache because of drug abuse.

Signs and Symptoms Of Phenobarbital Addiction And Abuse

Common signs and symptoms of addiction and abuse of this medication are similar and almost indistinguishable from abuse of other sedative-hypnotics and central nervous system depressants. However, abuse can be suspected when a maladaptive pattern of use leads to clinically significant impairment or distress, as manifested by the following psychosocial, behavioral and/or physical signs, usually manifesting themselves within a 12-month period.

Physical Signs And Symptoms Of Addiction And Abuse

Physical signs of abuse or addiction manifest when increased dosages of the drug are consumed by the patient. These signs can include:

  • Slurring speech
  • Sluggishness
  • Slow or shallow breathing
  • Bradycardia
  • Hypotension
  • Nystagmus, Diplopia or Strabismus
  • Ataxic gait and incoordination
  • Positive Romberg’s sign which refers to the inability of the patient to stand still with their feet together while their eyes are closed.
  • Muscular Hypotonia
  • Decreased superficial reflexes.

Psychological And Behavioral Signs And Symptoms Of Addiction And Abuse

Psychological and behavioral signs and symptoms are much less specific and can be said to be shared among all patients who suffer from substance abuse disorder. A characteristic behavioral patterns of a patient who many be abusing barbiturates may include:

  • An individual who is using prescription barbiturates in greater amounts, with greater frequency, or for a longer period of time than indicated by a prescribing physician
  • An individual who uses sedative-hypnotics in situations in which it is physi­cally hazardous to themselves, sometimes referred to as “risky use”
  • A persistent desire or unsuccessful efforts to cut down or control barbiturate use
  • Attempting to malinger, steal or to obtain multiple prescriptions from multiple doctors for barbiturates
  • A pattern of apprehensiveness, anxiety, and deceit regarding one’s barbiturate use.
  • Argumentativeness or aggression when their barbiturate use is questioned

These are not the only behavioral clues to substance abuse but some of the most characteristics. In addition to these, there are some cognitive and psychological clues as well:

  • Difficulty thinking
  • Poor memory
  • Faulty judgment
  • Disinhibited sexual aggressive impulses
  • Narrowed range of attention
  • Emotional lability and mood swings
  • Exaggerated basic personality traits
  • Hostility and Irritability
  • Paranoid and suicidal ideation
  • Anxiety and social withdrawal
  • Depression

Dangers of Phenobarbital Misuse And Addiction

There are numerous health hazards of barbiturate misuse and addiction. As previously stated the disinhibited and aggressive behavior may cause the patient to become assaultive and disorderly for which they may be arrested. There is further risk of injury or harm to one’s self as well as others while intoxicated.

Intravenous abuse is even more dangerous to one’s health. Unsterile self-injection may lead to sepsis, endocarditis, hepatitis, HIV/AIDs, thrombophlebitis, gangrene, and possible abscess formation and necrotic ulceration of the injection site.

Fatal overdose is also a common danger of abuse. Barbiturates have a very steep slope of function and only 2-3 times the normal dose is needed to produce fatal respiratory depression. Additionally, regarding overdose, it is particularly dangerous as there is no antidote for barbiturates.

How One Can Treat Phenobarb Addiction

Phenobarbital abuse and addiction is quite a real possibility with incorrect usage, however this medication is rarely used today and has been supplanted by more safe alternatives. With regard to managing addiction to this medication, it is best to opt for a drug rehab program at a rehabilitation center which is tailored to meet the needs of inpatients and outpatients during their recovery depending on the severity of their addiction. A rehab center provides various treatment programs inclusive of detoxification, medication-assisted therapy, behavioral therapy, counseling, and others, to help ensure that the individual attains complete healing and recovery from their drug dependency.

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Page Sources

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Published on: July 3rd, 2019

Updated on: October 22nd, 2021

About Author

Roger Weiss, MD

Dr. Roger Weiss is a practicing mental health specialist at the hospital. Dr. Weiss combines his clinical practice and medical writing career since 2009. Apart from these activities, Dr. Weiss also delivers lectures for youth, former addicts, and everyone interested in topics such as substance abuse and treatment.

Medically Reviewed by

Michael Espelin APRN

8 years of nursing experience in wide variety of behavioral and addition settings that include adult inpatient and outpatient mental health services with substance use disorders, and geriatric long-term care and hospice care.  He has a particular interest in psychopharmacology, nutritional psychiatry, and alternative treatment options involving particular vitamins, dietary supplements, and administering auricular acupuncture.