Benzodiazepines vs Barbiturates: Is One Class of Drugs Better?

Last Updated: June 24, 2020

Authored by Sharon Levy, MD, MPH

Reviewed by Michael Espelin APRN

Barbiturates and benzodiazepines are two types of drugs that are very similar in some respects but quite different in others. In fact, they are often confused with each other. Barbiturates and benzodiazepines both belong to the same broad classification of medications called sedative-hypnotics. They similarly affect the human body. Yet, there are significant differences between barbiturates and benzodiazepines. Mistaking one for the other can have dangerous consequences.

What is the barbiturates vs. benzodiazepines mechanism of action? Is one better or safer than the other? Are both types of drugs addictive? Here’s an overview of all the similarities and differences between benzodiazepines and barbiturates.

Benzos vs. Barbiturates: Are They the Same?

Benzodiazepines and barbiturates are not the same. They are two separate types of drugs that are often mistaken for each other. This is probably because they are both sedative-hypnotics. They similarly affect the body. Both are central nervous system depressants and cause drowsiness or sedation. They are used to treat similar medical conditions, including anxiety, panic attacks, insomnia, and seizures.

Some of the commonly prescribed benzos include Valium (diazepam), Xanax (alprazolam), and Ativan (lorazepam). A list of barbiturates widely used by doctors includes Seconal (secobarbital), Amytal (amobarbital), and Nembutal (pentobarbital).

A significant difference between barbiturate and benzodiazepine is that the former was introduced in the early 1900s while the latter was discovered in the mid-1950s. Therefore, benzodiazepines came onto the market several decades later. They were marketed as a more effective and less dangerous alternative to barbs.

Barbiturates and Benzodiazepines: Similar Features

Barbiturates and benzodiazepines are sedative-hypnotics and central nervous system depressants. They are both classified as controlled substances by the United States Drug Enforcement Administration. Both these types of drugs can be used to treat similar medical conditions, for example, seizures and insomnia. They also have some common side effects such as drowsiness, dizziness, nausea, and vomiting.

Barbiturate vs. benzodiazepine both have the potential for abuse. Benzos are abused more in current times compared to barbs. Due to their similar effect, they are known on the street as downers. Both produce feelings of euphoria, relaxation, well-being, and sedation. Moreover, cross-tolerance develops quickly to both, and a person needs more and more to achieve similar effects. Also, if a person lowers the dosage or stops taking either of them suddenly, withdrawal symptoms can occur. Both types of medications are tested on urine drug screens.

two urine drug test samples

Barbiturates mechanism of action is similar to benzodiazepines. Both act on a neurotransmitter called GABA. They reduce nerve activity in the brain. Because they slow down the functioning of neurons in the brain, it can be dangerous to combine either of them with other CNS suppressants like alcohol. This can lead to hazardous depression in respiratory function and excessive sedation. In severe cases, it may cause coma and death.

Difference Between Benzodiazepines and Barbiturates

The two types of drugs are different in many ways. For example, some of the side effects of barbiturates are not the same as those caused by benzodiazepines. Also, the addiction potential and risk of death from overdose is different. Furthermore, false-positive for barbiturates have been documented with commonly prescribed NSAIDs such as ibuprofen and Naproxen. On the other hand, sertraline has been reported as a potential cause of false-positive benzodiazepine results on urine drug screens.

Here is a summary of barbiturate vs. benzodiazepine differences:

Feature Benzodiazepines Barbiturates
Discovery/Development 1950s 1900s
Uses Anxiety, depression, panic, agitation, psychosis, insomnia, muscle tension, seizures, alcohol dependence Anesthetic, anticonvulsant, migraine headaches, alcohol poisoning
Potency Less More
Toxicity Lower Higher
Side Effects Memory problems, confusion, appetite changes, weight gain, constipation, dry mouth, fatigue, and reduced libido Headache, dizziness, and abdominal pain
Availability on the black market Common Rare
Addiction potential Lower Higher

Barbiturates vs. Benzo: Is One Better Than the Other?

Benzos are a newer class of drugs that have primarily replaced barbs which are an older type of medication. This has happened for several reasons. Benzodiazepines are less toxic and have fewer drug interactions. They are also known to have a better safety profile and superior efficacy.

It is important to note that benzo vs. barbiturate mechanism and effects on the human body are somewhat similar. So, even though benzos are believed to be a safer alternative, each of the types of medications has its pros and cons. For example, barbs are useful in headache treatment, while benzos not so much. It is always better to consult a prescribing physician before choosing between the two.

Drug Interactions and Combination Use

Benzodiazepines vs. barbiturates mechanism of action for both is on the GABA receptor complex in the brain. This means that the two types of medications have a synergistic or additive effect when used in combination. Therefore, mixing benzodiazepines and barbiturates can result in:

  • Increased feelings of wellbeing and euphoria
  • Reduced anxiety or stress
  • Excessive sedation or drowsiness
  • Altered motor function, coordination, and balance
  • Slurred speech
  • Lethargy
  • Problems with response time, perception, concentration, and attention
  • Muscle weakness
  • Loss of appetite, nausea, vomiting
  • Anger, aggression, violence
  • Mood swings
  • Hallucinations or delusions
  • Increased likelihood to engage in risky behaviors
  • Significant respiratory suppression with a lack of oxygen supply to vital organs
  • Physical and psychological dependence leading to a substance use disorder

woman feeling hard to breathe

Safety Issues with Benzos vs. Barbiturates

While there are many similarities between the two, the truth is that benzodiazepines and barbiturates are different and potentially very dangerous when used together.

It is worth noting that certain barbiturates such as butalbital are sometimes found in headache medicine (for example, Esgic, Fiorinal, Fioricet). A person taking these headache pills may not be aware of this fact and may combine it inadvertently with a benzodiazepine. Therefore, both these types of medicines must be made only by prescription and under close supervision by a physician.

If anyone is abusing barbiturates vs. benzodiazepines or both, it is crucial to seek professional care. Such a person is at risk of significant medical complications, overdose, and death. A licensed addiction treatment specialist can ensure withdrawal from these potent drugs in a safe and relatively comfortable manner. Due to their highly addictive nature, drug rehabilitation is usually necessary to prevent relapse.

Page Sources

  1. Kevin M. Nasky, DO, George L. Cowan, MD, MS, and Douglas R. Knittel, MD. False-Positive Urine Screening for Benzodiazepines: An Association with Sertraline? A Two-year Retrospective Chart Analysis. Psychiatry (Edgmont). 2009 Jul; 6(7): 36–39.
  2. Jeffrey Guina, Brian Merrill. Benzodiazepines I: Upping the Care on Downers: The Evidence of Risks, Benefits and Alternatives. J Clin Med. 2018 Feb; 7(2): 17.
  3. DeLorey TM, Kissin I, Brown P, Brown GB. Barbiturate-benzodiazepine interactions at the gamma-aminobutyric acidA receptor in rat cerebral cortical synaptoneurosomes. Anesth Analg. 1993 Sep;77(3):598-605.

Published on: August 12th, 2019

Updated on: June 24th, 2020

About Author

Sharon Levy, MD, MPH

After successful graduation from Boston University, MA, Sharon gained a Master’s degree in Public Health. Since then, Sharon devoted herself entirely to the medical niche. Sharon Levy is also a certified addiction recovery coach.

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.


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