What Are Benzodiazepines?

Benzodiazepines (BZDs) are central nervous system depressants, or tranquilizers. They slow down brain activity, relax muscles, calm jittery nerves, and induce sleepiness. Short-term use of benzodiazepines can treat anxiety, insomnia, panic disorder, social phobias, and seizures.

However, long-term use can lead to prescription drug addiction or misuse. Combining BZDs with other substances, such as alcohol or opioids, is dangerous. All benzodiazepines come with black box warnings (the Food and Drug Administration's strictest drug warning) to improve safe use.

This article describes the different types of benzodiazepines, how they work, their uses, side effects, and more.

Uses

Benzodiazepines are primarily used as sedatives to relieve anxiety, stop panic attacks, and help people sleep. However, BZDs have a wide range of uses. They can be prescribed to treat:

• Anxiety symptoms
• Generalized anxiety disorder
• Panic attack symptoms
• Panic disorder
• Social phobias
• Insomnia
• Major depressive disorder
• Seizures
• Alcohol withdrawal symptoms
• Sedation before, during, and after surgery
  

How Do Benzodiazepines Work?

Benzodiazepines are central nervous system (CNS) depressants. They work by binding with inhibitory gamma-aminobutyric acid (GABA) neurotransmitter receptors in the brain and throughout the central nervous system to block messages of fear, anxiety, and distress.

In doing so, they calm nerves, reduce anxiety, relax muscles, and cause drowsiness.

Benzodiazepine Types

There are many different types of benzodiazepines. The most commonly prescribed BZDs are:

• Valium (diazepam)
• Xanax (alprazolam)
• Klonopin (clonazepam)
• Ativan (lorazepam)
• Restoril (temazepam)

Benzodiazepines are typically prescribed as tablets or capsules. Occasionally, they are administered as injectables or suppositories.

All BZDs are categorized as Schedule IV controlled substances and come with the FDA's strictest black box warning.

Different benzodiazepine types have different "onset of action" times, which affect how long it takes for them to start taking effect and how long they stay in your body.

Benzodiazepines are classified based on what's called their elimination half-life, which means:

• Short-acting BZDs have an average half-life elimination rate ranging from one to 12 hours.
• Long-acting BZDs have a half-life ranging between 40 and 250 hours.

It takes about five half-lives to eliminate a drug from the body.

Some BZDs have a fast onset of action and kick in within a few minutes. Others have a slower onset of action and don't reach peak levels for over an hour.

Faster-acting benzodiazepines with a shorter half-life are generally considered more addictive. They have a greater risk of dependence and a higher rate of misuse.

Side Effects and Risks

The most common side effects of benzodiazepines are:

• Drowsiness
• Decreased alertness
• Lethargy
• Fatigue

Low libido (sex drive) and erectile dysfunction (ED) are also side effects. A 2013 study found that men taking benzodiazepines were two to three times more likely to have ED.

At higher dosages or with prolonged use, benzodiazepines can also lead to the following side effects:

• Aggressive behavior
• Blurred vision
• Confusion or disorientation
• Dizziness
• Impaired motor coordination
• Irritability
• Mood swings
• Slurred speech
• Vertigo (spinning sensation)

Because these drugs slow reaction times, they can also increase the risk of having an accident when driving a motor vehicle or operating heavy machinery.

Drug Interactions

Benzodiazepines exaggerate the effects of alcohol and other medications. Although it's possible to overdose on Valium, Xanax, or other BZDs when used alone, substances such as alcohol and opioids cause drug interactions that significantly increase overdose risk when combined with BZDs.

Flumazenil counteracts the sedative effect of benzodiazepines. It's FDA-approved as a benzodiazepine antagonist and can be a lifesaving treatment during an overdose.

Misuse

Benzodiazepine misuse is an ongoing public health concern.

When Valium was first introduced in 1963, healthcare providers thought it was less likely to cause dependence than previous sedatives. It wasn't until many years later that providers and the FDA discovered that long-term use of benzodiazepines often leads to dependence and misuse.

A 2019 study of benzodiazepines being taken as prescribed vs. misused found that misuse accounted for 17.2% of overall use. Adults age 50 and older were more likely than younger adults to misuse benzodiazepines as a sleep aid, and to take them more often than prescribed.

Another study found that between 2000 and 2015, teenagers' exposure to benzodiazepines increased by 54%. Almost half of these exposures were documented as intentional overuse or misuse.

Summary

Benzodiazepines (BZDs) are tranquilizers that act as central nervous system depressants. They exert sedative effects, calm nerves, and reduce anxiety.

BZDs work by binding with inhibitory-GABA neurotransmitter receptors to block signals of anxiety and distress to the brain. Because of their rapid onset of action and ability to provide quick symptom relief, BZDs effectively treat anxiety, panic disorders, sleep issues, and seizures.

Despite their effectiveness, BZDs have the potential to be highly addictive, which can lead to misuse. Common side effects include drowsiness, dizziness, fatigue, and more.

A Word From Verywell

Benzodiazepine use can be controversial. While benzodiazepines have benefits and may be the best treatment option for some people, the potential for addiction and misuse presents significant risks. As with any prescription medication, it's important to discuss your concerns with a healthcare provider and weigh the risks and benefits associated with using benzodiazepines for your health.