Benzodiazepines Drug Class

Benzodiazepinesare a class of drugs primarily used for treating anxiety, but they also are effective in treating several other conditions. The exact mechanism of action of benzodiazepines is not known, but they appear to work by affecting neurotransmitters in the brain, chemicals that nerves release in order to communicate with other nearby nerves. One of these neurotransmitters is gamma-aminobutyric acid (GABA), aneurotransmitterthat suppresses the activity of nerves. Scientists believe that excessive activity of nerves may be the cause of anxiety and other psychological disorders, and benzodiazepines reduce the activity of nerves in the brain andspinal cordby enhancing the effects of GABA.

For what conditions are benzodiazepines used?

Benzodiazepines are used for treating:

• anxiety and panic
• seizures (convulsions), and
• insomnia or trouble sleeping.

They also are used for:

• general anesthesia,
• sedation prior to surgery or diagnostic procedures,
• muscle relaxation,
• alcohol withdrawal and drug-associated agitation,
• nausea and vomiting,
• depression, and
• panic attacks.

Benzodiazepines differ in how quickly they start working, how long they continue to work, and for what they are most commonly prescribed.

• Diazepam(Valium) andclorazepate(Tranxene) have fast onsets of action and usually start working within 30 to 60 minutes.
• Oxazepam(Serax) has a slow onset, andlorazepam(Ativan),阿普唑仑(Xanax), andclonazepam(Klonopin) have intermediate onsets of action.
• Clorazepate (Tranxene),midazolam(Versed), andtriazolam(Halcion) are short-acting agents with a duration of action of 3 to 8 hours.
• Alprazolam (Xanax), lorazepam (Ativan),estazolam(ProSom), andtemazepam(Restoril) are intermediate-acting agents with a duration of action of 11 to 20 hours.
• Chlordiazepoxide(Librium), clonazepam (Klonopin), diazepam (Valium),flurazepam(Dalmane), and quazepam are long-acting agents with a duration of action of 1 to 3 days.

Although most benzodiazepines are used interchangeably, different benzodiazepines are often preferred for specific conditions due to their unique pharmacological properties and side effect profiles.

1. Alprazolam (Xanax), chlordiazepoxide (Librium), clorazepate (Tranxene), diazepam (Valium), lorazepam (Ativan), and midazolam are used foranxiety disorders.
2. Clonazepam (Klonopin), clorazepate (Tranxene), lorazepam (Ativan),clobazam(Onfi), and diazepam (Valium) are used forseizure disorders.
3. Estazolam (Prosom), flurazepam (Dalmane), quazepam (Doral), temazepam (Restoril), and triazolam (Halcion) are used forinsomnia or trouble sleeping.
4. Midazolam (Versed), lorazepam (Ativan), and diazepam (Valium) are used inanesthesia.
5. Diazepam (Valium) also is used formuscle relaxation.
6. Chlordiazepoxide (Librium) is used foralcohol withdrawal.

The most common side effects associated with benzodiazepines are:

• sedation,
• dizziness,
• weakness, and
• unsteadiness.

Other side effects include:

• transient drowsiness commonly experienced during the first few days of treatment,
• a feeling of depression,
• loss of orientation,
• headache,
• sleep disturbance,
• confusion,
• 易怒,
• aggression,
• excitement, and
• memory impairment.

All benzodiazepines can cause physical dependence. Suddenly stopping therapy after a few months of daily therapy may be associated withwithdrawal symptomswhich include a feeling of loss of self-worth, agitation, and insomnia. If benzodiazepines are taken continuously for longer than a few months, stopping therapy suddenly may produce seizures, tremors, muscle cramping, vomiting, and sweating. In order to avoid withdrawal symptoms, the dose of benzodiazepines should be tapered slowly.

All benzodiazepines cause excessive sedation when combined with other medications that slow the brain's processes (for example, alcohol,barbiturates, narcotics, and tranquilizers).

• The elimination of some benzodiazepines (for example, alprazolam [Xanax] and diazepam [Valium]) is reduced by drugs that slow the elimination of drugs in the liver (for example,ketoconazole[Nizoral,Xolegel],valproic acid[Depakene,Stavzor],cimetidine[Tagamet], andfluoxetine[Prozac]).
• Reduced elimination may result in increased blood concentrations and side effects from the affected benzodiazepines.
• Antacids may reduce the rate of absorption of benzodiazepines from the intestine.
• Separating the administration of antacids and benzodiazepines by several hours may prevent this interaction.

Approved benzodiazepines in the United States include:

• 阿普唑仑(Xanax)
• chlordiazepoxide (Librium)
• clonazepam (Klonopin)
• clorazepate (Tranxene)
• diazepam (Valium)
• estazolam (Prosom)
• flurazepam (Dalmane)
• lorazepam (Ativan)
• midazolam (Versed)
• Nayzilam
• ONFI
• oxazepam (Serax)
• Seizalam
• Sympazan
• temazepam (Restoril)
• 三唑仑(酣乐欣)
• quazepam (Doral)
• Valtoco

Two serious concerns of benzodiazepine therapy are

• the potential for abuse (overdose) and
• 自然史的发展l dependence (addiction).

Although intentional abuse of prescription benzodiazepines is relatively uncommon in the general population, it should be used more cautiously in individuals with a history of drug abuse as they are at the greatest risk for seeking benzodiazepines to experience a "high."

• Benzodiazepines are rarely the sole drug of abuse, and abusers usually combine benzodiazepines with other drugs to increase the effect. For example, benzodiazepines are combined with certain opioids, a class of strong prescription pain relievers, to enhance the euphoric effects.
• Among abusers, diazepam (Valium) and alprazolam (Xanax) are the most popular due to their rapid onset.
• For most patients, the use of a benzodiazepine for a period of several months does not seem to cause issues of addiction, tolerance, or difficulties in stopping the medication when it is no longer needed.
• However, several months of use significantly increases the risk for addiction, tolerance, and appearance of withdrawal symptoms with dose reduction or termination of therapy.

Abusers are at higher risk for side effects including

• confusion,
• slurred speech,
• seizures or convulsions,
• severe drowsiness or coma,
• shakiness,
• slow heartbeat,
• difficulty breathing, and
• severe weakness.

Benzodiazepine addicts also have a higher risk of developingdementia, an illness affecting the brain that causes gradual memory loss and problems with language and motor skills, in the long term.

The dangers of benzodiazepine addiction are many. Fatal cases of overdose have been reported with the use of benzodiazepines.

• Each year benzodiazepine overdose contributes to a significant number of trips to the emergency room and hospital admissions.
• Theantidotefor benzodiazepine overdose isflumazenil(Romazicon).
• To treat benzodiazepine overdose, flumazenil is injected rapidly into the vein.

When benzodiazepine treatment is stopped abruptly, patients may develop withdrawal symptoms. Factors that increase the risk and severity of withdrawal symptoms include high doses and long-term benzodiazepine use. Additionally, withdrawal symptoms tend to occur earlier with benzodiazepines with short elimination half-lives.

Common symptoms of benzodiazepine withdrawal include

• anxiety,
• trouble sleeping,
• restlessness,
• muscle tension, and
• irritability.

Less commonly, patients may also experience

• nausea,
• malaise,
• blurred vision,
• sweating,
• nightmares,
• depression,
• muscle coordination problems,
• tremors, and
• muscletwitchingor spasms.

In rare cases,

• hallucinations,
• delusions,
• seizures, and
• ringing in the earsmay also occur.

The risk of withdrawal seizures is higher with a high benzodiazepine dose, long treatment duration, and concurrent use of medications that lower theseizurethreshold. Prompt recognition and treatment of benzodiazepine withdrawal are crucial as this condition may be life-threatening.

Benzodiazepine withdrawal is treated with intravenous (injected into the vein) benzodiazepines such as diazepam (Valium) which tend to work over a longer period of time.