Difference Between Benzodiazepines and Barbiturates

The key difference between benzodiazepines and barbiturates is that barbiturates cause a high neuronal depression when compared to benzodiazepines.

Benzodiazepines and barbiturates are drugs that are useful in medicine. Benzodiazepines have the structure of a benzene ring that is fused with a diazepine ring while barbiturates are chemical derivatives of barbituric acid.

1. Overview and Key Difference
2. What are Benzodiazepines
3. What are Barbiturates
4. Side by Side Comparison – Benzodiazepines vs Barbiturates in Tabular Form
5. Summary

What are Benzodiazepines?

Benzodiazepine is a type of psychoactive drugs having the chemical structure made out of the fusion of a benzene ring and a diazepine ring. We can abbreviate this drug name as BZD, BDZ or BZs. The first member of this drug class is chlordiazepoxide (Librium). This drug was accidentally discovered by Leo Sternbach in 1955. In 1977, this drug was the most prescribed medication globally. The family of this type of drugs is named as minor tranquillizers.

This drug can enhance the neurotransmitter gamma-aminobutyric acid (GABA receptor). This results in sedative-hypnotic (sleep-inducing effect), anxiolytic (anti-anxiety effect), anticonvulsant effects, and muscle relaxant properties. Moreover, high doses of this drug can cause anterograde amnesia and dissociation. Therefore, this drug is useful in treating anxiety, insomnia, agitation, seizures, muscle spasms, alcohol withdrawal, etc.

Difference Between Benzodiazepines and Barbiturates

Figure 01: Structures of Two Common Benzodiazepines

Generally, benzodiazepines are considered safe and effective for short term usage; 2 to 4 weeks. However, cognitive impairment and paradoxical effects such as behavioural disinhibition and aggression can occasionally occur. Sometimes, people can have paradoxical reactions such as worse agitation of panic. Furthermore, this drug is associated with an increased risk of suicide.

When considering the chemical structure of benzodiazepines, they share a similar chemical structure and the effect on humans is caused by the allosteric modification of a specific kind of neurotransmitter receptor named GABA receptor. This can result in the increase of overall conductance of these inhibitory channels that can cause various therapeutic effects, including the adverse effects of this drug.

What are Barbiturates?

Barbiturates are a class of drugs that can act as a central nervous system depressant. These drugs are effective as anxiolytics, hypnotics, and anticonvulsants. However, this drug has been largely replaced by benzodiazepines in routine medical practice which particularly include the treatment of anxiety and insomnia. But it is still in use for many purposes, including the general anaesthesia, epilepsy, treatment of acute migraine, cluster headaches, euthanasia, and assisted suicide.

Key Difference - Benzodiazepines vs Barbiturates

Figure 02: Parent Structure of Barbiturates: Barbituric Acid

This drug acts by working as positive allosteric modulators, and it can also act as GABA receptors at higher doses. Barbiturates are relatively nonselective compounds that can bind to an entire superfamily of ligand-gated ion channels, and GABA receptor channel is only one of several representatives.

What is the Difference Between Benzodiazepines and Barbiturates?

Benzodiazepines and barbiturates are drugs that are useful in medicine. The key difference between benzodiazepines and barbiturates is that benzodiazepines cause less neuronal depression, whereas barbiturates cause a high neuronal depression. Moreover, benzodiazepines are useful in treating anxiety, insomnia, agitation, seizures, muscle spasms, alcohol withdrawal, etc. while barbiturates are useful in general anaesthesia, epilepsy, treatment of acute migraine, cluster headaches, euthanasia, and assisted suicide.

Below is a summary of the difference between benzodiazepines and barbiturates in tabular form.

Summary – Benzodiazepines vs Barbiturates

Benzodiazepines and barbiturates are drugs that are useful in medicine. The key difference between benzodiazepines and barbiturates is that benzodiazepines cause a less neuronal depression, whereas barbiturates cause a high neuronal depression.

Reference:

1. “Benzodiazepines Drug Class: Side Effects, Types & Uses.” RxList, Available here.

Image Courtesy:

1. “Benzodiazepine3” By Boghog2 – Own work (Public Domain) via Commons Wikimedia
2. “Barbituric-acid-structural” By Manuel Almagro Rivas – Own work (CC BY-SA 4.0) via Commons Wikimedia