Benzodiazepines are a class of psychoactive drugs used to treat a range of conditions, including anxiety and insomnia. They are one of the most widely prescribed medications in the United States, particularly among elderly patients.
The first benzodiazepine - chlordiazepan - was accidentally developed in 1955 by Leo Sternbach and, since then, many more have been designed.
Benzodiazepines possess sedative, hypnotic, anti-anxiety, anticonvulsant, and muscle relaxant properties.
They work by enhancing the effect of the neurotransmitter gamma-aminobutyric acid (GABA) - which is responsible for reducing the activity of neurons that cause stress and anxiety.
Short term use of these medications is generally safe and effective. However, the long term use of benzodiazepines is controversial, because of the potential of tolerance, dependence, and other adverse effects.
In this article, we will look at how benzodiazepines work, what they are used for, and any related side effects and risks.
Fast facts on benzodiazepines
Here are some key points about benzodiazepines. More detail and supporting information is in the main article.
- Benzodiazepines are used for a range of health issues
- They enhance the inhibitory activity of GABA in the central nervous system
- Long-term use of benzodiazepines can result in physical dependence
Medical uses of benzodiazepines
Benzodiazepines were first discovered in 1955.
- Generalized anxiety disorder (GAD) - benzodiazepines are often used in the treatment of GAD. The National Institute of Health and Clinical Excellence (NICE) recommends the use of benzodiazepines for short term GAD treatment for no longer than 1 month. Selective serotonin reuptake inhibitors (SSRIs) are considered to be more effective at treating long-term GAD.
- Insomnia - as benzodiazepines can lead to dependence, they are normally only used as a short-term treatment for severe insomnia or on an "irregular/as-needed" basis.
- Seizures - benzodiazepines are powerful anticonvulsants and are very effective at preventing prolonged convulsive epileptic seizures. The first-line hospital choices for treating seizures are clonazepam, diazepam, or lorazepam.
- Alcohol withdrawal - the most common benzodiazepine prescribed for alcohol withdrawal is chlodiazepoxide, followed by diazepam. The drugs help alcoholics with detoxification and reduce their risk of severe alcohol withdrawal effects.
- Panic attacks - because of their rapid anti-anxiety effects, benzodiazepines are very effective at treating anxiety associated with panic disorder. The American Psychiatric Association says that their use for initial treatment is strongly supported by many different study trials. However, United Kingdom-based NICE says that long-term use of benzodiazepines for the treatment of panic disorder is not recommended.
Mechanism of benzodiazepines
The human brain contains many different neurotransmitters which are responsible for sending messages between brain cells, these messages can have either "tranquilizing" or "excitatory" effects.
When someone feels overly anxious, the brain becomes "excited" and over-active, tranquilizing transmitters need to quickly send messages to brain cells to slow down activity in the brain and reduce the symptoms of anxiety.
GABA is the brain's tranquilizing neurotransmitter, and billions of brain cells respond to its signals.
Benzodiazepines work by enhancing the effect of the neurotransmitter GABA. The drugs contain chemicals which add to the calming effect already produced by the human body and essentially keep the brain in a more "tranquilized" state.
Types of benzodiazepines
There are many different benzodiazepines; they all differ in potency, the speed at which they are metabolized, and their therapeutic use.
- Alprazolam (Xanax) - FDA approved for the treatment of panic and anxiety disorders. Alprazolam is the most prescribed benzodiazepine in the U.S.
- Chlordiazepoxide (Librium) - used for the management of alcohol withdrawal syndrome.
- Clorazepate (Tranxene) - a hypnotic, sedative, anxiolytic drug used to treat severe insomnia and anxiety disorders.
- Diazepam (Valium) - an anxiolytic, hypnotic, sedative, and anticonvulsant drug with rapid onset. It is used to treat panic attacks, insomnia, seizures, restless leg syndrome, and alcohol withdrawal. Diazepam is also used for the treatment of benzodiazepine dependence because of its low potency.
- Estazolam - a sedative, anxiolytic drug prescribed for short term treatment of insomnia.
- Flurazepam (Dalmane) - a sedative, anxiolytic drug used to treat mild to moderate insomnia.
- Loprazolam (Somnovit) - a sedative, anxiolytic drug used to treat moderately severe insomnia.
- Oxazepam - used to treat anxiety and insomnia and control the symptoms of alcohol withdrawal.
- Temazepam (Restoril) - approved for the short-term treatment of insomnia.
- Triazolam (Apo-Triazo, Halcion, Hypam, and Trilam) - only used as a sedative to treat severe insomnia.
Side effects and risks of benzodiazepines
Side effects of benzodiazepine usage may include:
- Impaired coordination
- Vision problems
- Feelings of depression
Long-term use of benzodiazepines can also result in physical dependence. The withdrawal symptoms of benzodiazepines include trouble sleeping, feelings of depression, and sweating.
If someone has become dependent on a benzodiazepines, it is crucial that they do not suddenly stop therapy cold turkey. Stopping cold turkey can result in life-threatening seizures, tremors, and muscle cramps. Therefore, it is important to taper off benzodiazepines very slowly with professional help.
Benzodiazepine overdose is rarely fatal unless the drugs are mixed with barbiturates, opioids, alcohol, or tricyclic antidepressants.
The most common symptoms of benzodiazepine overdose are central nervous system depression and intoxication with impaired balance and movement control and slurred speech.
Flumazenil can be used as an antidote, but more often than not, the patient is simply observed and supported until the body has naturally cleared the drug.
Drug interactions with benzodiazepines
Before beginning treatment with a benzodiazepine, it is important to tell the doctor about every medication currently being taken.
Some drugs, including antidepressants and oral contraceptives can cause excessive drug accumulation and increased side effects of benzodiazepines.
In contrast, St. John's wort, the antibiotic rifampicin, and the anticonvulsants carbamazepine and phenytoin decrease the effectiveness of benzodiazepines.
Most importantly, patients should never mix benzodiazepines with alcohol or opioids, the interaction can be life-threatening.
Misuse of benzodiazepines
Abuse of benzodiazepines is becoming a serious public health issue. According to the Substance Abuse and Mental Health Services Administration (SAMHSA), hospital admissions among people over the age of 12 related to the abuse of benzodiazepine drugs rose from 22,400 in 1998 to approximately 60,200 in 2008.
"The misuse of benzodiazepines along with other prescription drugs is fueling the rise of treatment admissions. Prescription drug misuse is dangerous and can even be deadly.
Everyone has a role to play in helping to prevent prescription drug misuse. Simple steps such as locking up medications and proper disposal of unused medications are easy ways people can contribute to reducing the problem."
Pamela S. Hyde, SAMHSA administrator