Benzodiazepines: What They Are, Uses, Side Effects & Risks (2024)

What are benzodiazepines?

Benzodiazepines are medications that make your nervous system less active. The decrease in nervous system activity makes these medications helpful for a variety of symptoms and conditions.

Many countries, including the U.S., classify benzodiazepines (sometimes known by the slang term “benzos”) as controlled substances. That means you need a prescription to get them. It’s illegal to have or obtain them (depending on the laws where you are) if you don’t have a prescription.

IMPORTANT: Benzodiazepines are controlled because they can have dangerous effects, especially when misused. They can also be habit-forming. Because of these factors, healthcare providers use benzodiazepines cautiously. If your nervous system’s activity drops too low, it can have dangerous or even deadly effects.

How do benzodiazepines work?

Your nervous system uses chemical and electrical signals to send and relay messages throughout your body. The chemical signals, known as neurotransmitters, can attach to cells with the right receptors. Neurotransmitters and receptors work much like your car keys. Neurotransmitters (your car key) can only fit into the right receptor (your car ignition). If it fits, the neurotransmitter can activate a process within the cell (starting your car).

Benzodiazepines tell your brain to release a neurotransmitter, gamma-aminobutyric acid (GABA). This neurotransmitter has a specific job: It makes your nervous system less active. The slowed activity can have the following effects:

• Amnestic: This word comes from a Greek word that means “forgetfulness.” Benzodiazepines temporarily block the formation of new memories (known as anterograde amnesia).
• Anxiolytic: This term is a combination of two Greek root words, “anxio” for “anxiety” and “lytic,” meaning “to loosen.” While active, medications with this effect “loosen’’ anxiety’s hold on you.
• Hypnotic: While many people associate “hypnotic’’ with the practice of hypnosis, this word actually comes from the name Hypnos, the Greek god of sleep. Just like their namesake, hypnotic medications make you sleepy.
• Sedative: This term comes from a Latin word that means “to settle.” In this context, benzodiazepines help your nervous system “settle down” and have a quieting effect.

Other ways to classify benzodiazepines

There are two main ways that experts classify benzodiazepines:

• Strength: Some benzodiazepines are stronger than others (though potency can vary from person to person for varying reasons). For example, 15 milligrams (mg) to 30 mg of flurazepam is generally equivalent to 0.25 mg to 0.5 mg of clonazepam.
• Duration of action: Some benzodiazepines are short-acting and last only several hours. Some are long-acting and last several days. Most long-acting benzodiazepines aren’t as strong.

The strength and duration of action of benzodiazepines are important in what conditions they treat. Short-term or emergency conditions usually merit the use of stronger, short-acting benzodiazepines. Chronic, non-emergency conditions are usually treatable with lower-strength, longer-acting benzodiazepines.

What conditions do benzodiazepines treat?

These medications treat conditions based on which effect they cause. While there are separate types because they have different primary effects, there’s a lot of overlap between them. For example, most benzodiazepines have a sedative effect in addition to their primary effect.

• Amnestic: These are common for beginning general anesthesia before surgeries and other medical procedures.
• Anxiolytic: These treat anxiety disorders, such as social anxiety disorder and panic disorder.
• Hypnotic: These treat insomnia and related sleep disorders.
• Sedative: This effect has many uses. It can treat conditions and symptoms related to muscle control, such as muscle spasms. It can also treat more severe issues like catatonia (which often happens with mental health conditions like schizophrenia or bipolar disorder). These benzodiazepines are also very important in treating seizures (including those due to epilepsy) and status epilepticus, a seizure-related medical emergency.

What are nonbenzodiazepines?

A few medications mimic the hypnotic effects and work similarly to benzodiazepines, but they aren't the same. Experts call these nonbenzodiazepines. These drugs also activate the same receptors as benzodiazepines and cause GABA release. Because of how they work, these drugs are most effective in treating insomnia and related sleep disorders. They include:

• Eszopiclone (Lunesta®).
• Zaleplon (Sonata®).
• Zolpidem (Ambien®).

Are benzodiazepines commonly prescribed?

Yes, benzodiazepines are commonly prescribed and see widespread use. In a 12-month period spanning 2014 and 2015, experts estimate that at least 30.5 million people in the U.S. took benzodiazepines prescribed by a healthcare provider.

What are the most commonly prescribed benzodiazepines?

The most common benzodiazepines approved in the United States include (but aren’t limited to):

• Alprazolam (Xanax®): Approved for treating anxiety disorders, panic disorder and premenstrual dysphoric disorder.
• Chlordiazepoxide (Librium®; brand name is no longer available in the U.S.): Approved for treating alcohol withdrawal and anxiety-related conditions.
• Clobazam (Onfi®, Sympazan®): Approved for treating seizures and certain forms of epilepsy.
• Clonazepam (Klonopin®): Approved to treat agitation, anxiety and seizures.
• Clorazepate (Tranxene®): Approved for treating anxiety and seizures.
• Diazepam (Diastat®, Valium®, Valtoco®): Approved to treat alcohol withdrawal, seizures and muscle spasms. Also approved for use as pre-anesthesia for surgery and procedures. These can also treat toxic effects on the heart from chloroquine and hydroxychloroquine.
• Estazolam (ProSom®; brand name is no longer available in the U.S.): Approved to treat insomnia.
• Flurazepam (Dalmane®; brand name is no longer available in the U.S.): Approved to treat insomnia.
• Lorazepam (Ativan®, Loreev®): Approved for treating seizures, chemotherapy-related nausea and vomiting, anxiety, pre-anesthesia for surgery and procedures, and phobias.
• Midazolam (Nayzilam®, Seizalam®, Versed®; brand name Versed is no longer available in the U.S.): Approved to treat seizures, sedate people on a ventilator, and as pre-anesthesia for surgery and procedures.
• Oxazepam (Serax®; brand name is no longer available in the U.S.): Approved as a treatment for alcohol withdrawal syndrome, anxiety and agitation.
• Quazepam (Doral®): Approved to treat insomnia and sleep problems.
• Remimazolam (Byfavo®): Approved for pre-anesthesia before surgeries and procedures.
• Temazepam (Restoril®): Approved for treating insomnia.
• Triazolam (Halcion®): Approved for treating insomnia.

Unapproved benzodiazepines

Many benzodiazepines aren’t approved for use in the United States. Some of these have approval in other countries, and some don’t have approval anywhere.

One benzodiazepine that’s noteworthy — even though it’s not approved (and illegal) in the United States — is flunitrazepam. This drug is best known as Rohypnol (or by the slang term “roofies”), and it’s infamous for its use as a “date rape” drug. As a result, flunitrazepam is a well-studied drug in the U.S. (and in many places worldwide). Healthcare providers can test for it and treat people under its influence (see below under “What are the disadvantages, side effects and complications that are possible with benzodiazepines?”).