Benzodiazepines

Types and differences of benzodiazepines

All benzodiazepines have similar effects, but differ in how quickly they work, how quickly they are metabolized, their potency and the duration of their actions, which is related to their half-lives (time required for a medication level to fall to half its initial concentration in the body). Examples of benzodiazepines include:

Indications for benzodiazepines

Benzodiazepines are used primarily to treat cases of significant anxiety. They should not be used to treat the type of stress, nervousness or tension that a person encounters in everyday life. Several anxiety disorders are commonly treated with benzodiazepines, including:

It appears that these disorders may at times be treated more effectively with antidepressant medications, which have the advantage of not being associated with the development of psychological dependence.

In some cases, benzodiazepines are used to treat insomnia, although they are typically effective for only a few weeks. In addition, certain benzodiazepines are commonly used in hospital settings to lessen patients’ anxiety before medical or surgical procedures.

Other anxiety disorders, such as obsessive-compulsive disorder and post-traumatic stress disorder, are usually treated with other classes of drugs, such as antidepressants.

Specific benzodiazepines are sometimes used to treat various conditions. For example:

Contraindications for benzodiazepines

Patients with a history of substance abuse may be more susceptible to developing a psychological dependence on benzodiazepines. In addition, patients with damage to their kidneys or liver may maintain higher levels of benzodiazepines in their bloodstream, increasing the risk of side effects.

Individuals with brain disease are likely to suffer higher incidences of central nervous system (CNS) depression. Starting or stopping use of benzodiazepines too suddenly can trigger seizures in these patients if they have used benzodiazepines for more than a few weeks continuously.

Before taking benzodiazepines, patients should tell their physician if they have ever had an allergic reaction to this type of medication, or to substances such as foods, preservatives or dyes.

Benzodiazepines also can worsen some medical conditions, including:

• Depression and other mental illnesses
• Emphysema, asthma, bronchitis or other lung disorders
• Glaucoma (eye disorder characterized by increased pressure in the eyeball)
• Hyperactivity
• Myasthenia gravis (disease marked by weakness of the skeletal muscles)
• Porphyria (metabolic abnormality that causes abdominal pains and mental confusion)
• Sleep apnea (temporary cessation of breathing during sleep)
• Swallowing difficulties

Potential side effects

Common side effects of benzodiazepines include marked drowsiness (which may be a therapeutic effect when used for insomnia) and impaired motor function.

Less common side effects include:

• Increased anxiety
• Confusion
• Fast, pounding or irregular heartbeat
• Memory lapses after the drug is taken
• Depression

In some patients, use of benzodiazepines may cause psychological or physical dependence if taken for a long time or in high doses. This risk is very low when benzodiazepines are taken for short periods of time under close physician supervision.

Signs that a patient may be dependent on benzodiazepines include a strong desire or need to take the drug, or a need to increase the dosage level to get the same medicinal effect. Patients who are dependent on these drugs also may exhibit withdrawal symptoms, including irritability, nervousness, insomnia, abdominal or stomach cramps, and trembling or shaking after ceasing use of the medication. Patients who exhibit signs of dependence should not stop taking their medication, but should visit a physician for correct intervention. Improper cessation of the medication can lead to severe withdrawal symptoms and even death. In addition to the symptoms listed above, other signs of withdrawal include:

• Tachycardia (rapid heartbeat)
• Increased blood pressure
• Muscle cramps
• Anxiety
• Panic attacks
• Impairment of memory and concentration
• Perceptual disturbances

Withdrawal symptoms can begin as early as one day after stopping use of the medication and may continue for weeks or months.

Some anti-anxiety drugs, including benzodiazepines, can build up in the system and cause toxicity if not monitored carefully. The risk is especially high for people who have conditions, such as kidney or liver diseases, that reduce the body’s ability to metabolize the drugs. Therefore, physicians monitor the use of benzodiazepines for potentially toxic build-up in the body.

Drug or other interactions

Patients should consult their physician before taking any additional prescriptions, over-the-counter medications, nutritional supplements or herbal medications. Of particular concern to individuals taking benzodiazepines are:

• Central nervous system (CNS) depressants. These medications cause drowsiness that may be increased when taken with benzodiazepines. Examples of CNS depressants include antihistamines, cold and hay fever medications, sedatives and tranquilizers, prescription pain medications, barbiturates, medicines for seizures, muscle relaxants, and anesthetics.
• Alcohol. Alcohol also serves as a CNS depressant. Use of alcohol with benzodiazepines can affect the heart and breathing and may increase drowsiness.
• Fluvoxamine or nefazodone. These antidepressant drugs may cause higher levels of benzodiazepines to remain in the system, thus increasing the hypnotic effects of the benzodiazepine and the risk of side effects.
• Itraconazole or ketoconazole. These antifungal drugs should not be used with benzodiazepines.
• Opioids. Benzodiazepines can interfere with the pain-killing effects of these medications.

Lifestyle considerations with benzodiazepines

Because benzodiazepine use frequently causes marked drowsiness, patients who take this medication should not drive, engage in dangerous physical activities or use hazardous machinery during the initial stages of treatment. Activities can be adjusted once patients become aware of their reaction to the medication.

Pregnancy use issues

Certain benzodiazepines – such as chlordiazepoxide and diazepam – have been shown to raise the risk of birth defects in children when used during the first three months of pregnancy. Although birth defects have not been linked to other benzodiazepines, similar problems are possible, as all benzodiazepines are related. Some benzodiazepines have been shown to cause birth defects or other serious problems in animal testing.

Excessive use of benzodiazepines during pregnancy has been linked to dependency in the baby after birth. Use of benzodiazepines during the last few weeks of pregnancy may cause various problems in newborn infants, including body temperature problems, breathing problems, feeding difficulties, drowsiness and muscle weakness. High doses of benzodiazepines given to a woman within 15 hours of delivery also can cause these symptoms.

Benzodiazepines have been shown to pass into breast milk and to cause drowsiness and difficulty in feeding. Weight loss may occur in both mothers and nursing infants.

Child use issues

Side effects associated with benzodiazepines are more likely to occur in children, especially very young children. There is evidence to suggest that using the benzodiazepine clonazepam may cause deficiencies in physical and mental growth of children. In many cases, these effects may not become evident until years later. For this reason, great care must be exercised in deciding whether to give benzodiazepines to children.

Pregnancy use issues

Side effects associated with benzodiazepines are more likely to occur in the elderly. In addition, benzodiazepines that are taken for insomnia are more likely to cause daytime drowsiness in older patients. The use of benzodiazepines appears to be associated with increased rates of falls and related injuries, most notably hip fractures, in the elderly.