Breaking News

Error rendering macro 'rss' : java.io.IOException: Failed to recover from an exception: http://environmentalhealthnews.org/archives_rss.jsp?sm=&tn=1title%2Clede%2Cdescription%2Ctext%2Csubject%2Cpublishername%2Ccoverage%2Creporter&tv=toxicology&ss=1

Benzodiazepines

Author

Overview


Benzodiazepines have been in use for over 30 years and are still widely prescribed in the treatment of anxiety disorders and other medical conditions. Benzodiazepines are classified as class C controlled substances within the Misuse of Drugs Act 1971, which means that possession of these drugs for personal use is not illegal, but supplying them to a person other through a doctor's prescription is illegal.

These drugs are classified as sedative-hypnotic agents, which depress or slow down the body, and this class of drugs includes many compounds that greatly vary in potency, metabolism, and clinical use. When taken alone, benzodiazepines have a relatively good safety record. Even when taken in overdose quantities, these drugs rarely cause serious consequences. Unfortunately, when benzodiazepines are being abused, they may be used in combination with other CNS-depressant agents such as barbiturates or alcohol, and it is these combinations that can lead to serious physical consequences, including depressed respiration, coma, and even death. Newer potent, short-acting agents have been considered the cause of death in many forensic cases.

Benzodiazepines were developed in the 1950s as a safer alternative to barbiturates. Currently, in the United States, only about 15 of these are approved by the FDA. The top four - alprazolam, clonazepam, diazepam and lorazepam - are consistently listed among the top 100 most commonly prescribed medications. Flunitrazepam, also known by the brand name Rohypnol and by the street names roofies, R2, roofinol, rope, rophies, forget-me pill, and Mexican valium, has recently received more press attention than most of the other benzodiazepines, especially on college campuses, where its use as a "date rape" drug has placed it on the watch list of students and police. Flunitrazepam is one of the drugs, along with MDMA (ecstasy), used by teenagers and young adults as part of the nightclub scene. It is usually consumed orally, often combined with alcohol, and can also be snorted after crushing the tablets.

Historical Background


The oldest group of tranquilizers was those based on barbiturate. However, during the 1950s and 1960s it became clear that use of these drugs was not without problems: dependence, and accidental and suicidal poisonings. Therefore, chemists began to search for a safer drug that could offer the benefits of barbiturates but without the serious problems that it was causing. Benzodiazepines offer all of the advantages of the earlier barbiturate-based products without some of the most dangerous side effects, but they are not without their own problems.

Tranquilizers including benzodiazepines and minor tranquilizers became a mainstay of treatment in the 1960s for many middle-class housewives throughout the United States. The practice of taking minor tranquilizers was so widespread during this time that they were made famous in the Rolling Stones' song "Mother's Little Helper." It is estimated that in the 1970s, as many as 30 million women were taking minor tranquilizers (almost 50% of the female population at that time). Psychiatrists were freely prescribing these minor tranquilizers to unhappy housewives, and many housewives became unknowingly addicted to these drugs. 

Therapeutic Usage



Physicians use benzodiazepines to treat many disorders, including a number of anxiety disorders such as acute anxiety, panic disorder, post-traumatic stress disorder, and obsessive-compulsive disorder. In addition, benzodiazepines are also used to treat insomnia and for the acute treatment of epileptic seizures, convulsive disorders, and spastic disorders.

Benzodiazepines depress the central nervous system and therefore reduce emotional reactions, mental alertness, and feelings of anxiety, bringing a sense of relaxation. Several studies have shown that impairment of acognitive or mental function can occur. For example, college students who take benzodiazepines before exams to help them relax or sleep may not remember some of what they have been studying. Common side effects of benzodiazepines include drowsiness, loss of coordination, unsteady gait, dizziness, and slurred speech. Some of the less common side effects include changes in sexual desire or ability, constipation, a false sense of well being, nausea and vomiting, urinary problems, and fatigue.

Harmful Side Effects


Serious side effects with these drugs are rare and include behavior problems such as outbursts of anger, depression, hallucinations, low blood pressure, muscle weakness, skin rash or itching, fever and chills, sores in the throat or mouth, unusual bruising or bleeding, extreme fatigue, etc. If any of these side effects occurs, a doctor should be contacted immediately.

Driving and hazardous work should not be performed while taking benzodiazepines because they can impair mental alertness and coordination. Persons taking any of the benzodiazepine medications should never drink alcohol. Use during pregnancy and nursing should be avoided as well.

Toxic Effects


Benzodiazepines have an extremely low risk of acute toxicity when they are used alone. Unfortunately, these drugs are often used with other medications, especially other CNS depressants, and this increases all the side effects of the benzodiazepine. Alcohol and benzodiazepines should never be taken together, since they can impair an individual's ability to breathe and dangerously lower blood pressures, which can result in coma and death.

Benzodiazepines enhance the action of the inhibitory neurotrasmiter gamma-aminobutyric acid (GABA) and also inhibit other neuronal systems. The result is generalized depression of spinal reflexes and the reticular activating system, and this can result in coma and respiratory arrest. CNS depression can be observed within 30-120 minutes of ingestion of benzodiazepines' toxic dose (toxic:therapeutic ratio for benzodiazepines is very high) and lethargy, slurred speech, ataxia, coma and respiratory arrest may occur.

Furthermore, benzodiazepines should not be used with other drugs that inhibit the CNS, including hypnotic agents, sedating antidepressants, neuroleptic agents, anticonvulsants, and even antihistamines. Combined use with the barbiturates and other sedatives, such as phenobarbitol, pentobarbital, secobarbitol and others can also increase sedation and depress breathing to dangerous levels. Combined use of more than one benzodiazepine is unnecessary and unsafe, as is combined use of benzodiazepines and sleeping pills.

Potential for Abuse


The personal and social consequences of benzodiazepine abuse have not, to date, been extensively studied. A few seminal studies have shown, however, that use and abuse of the benzodiazepines carry the possibilities of impaired decision-making, decreased learning skills, released aggression, and an impaired ability to empathize, all of which can have profound effects on an individual's educational, social, and workplace environments. Medical prescriptions are the primary source of benzodiazepines for those who abuse these drugs and some people addicted to benzodiazepines also use a practice known as "doctor shopping," where the patients obtain several prescriptions by continuously switching doctors. In this way, they can get enough of their drug, via a doctor, to keep up with their addiction. The doctors used by the patient are usually unaware that the patient has already been prescribed the same drug by another doctor. Another means of getting prescription drugs such as benzodiazepines is by buying the drug from a patient who has legitimately prescribed the medication. These "legitimate" patients can be friends, parents, relatives, or even people on the street offering their prescriptions in exchange for money.

Addiction to Benzodiazepines


Use of any of benzodiazepines for as little as four to six weeks can lead to psychological or physical dependence (even sooner in patients taking short-acting, high-potency benzodiazepines) that can be very profound. Signs of addiction to benzodiazepines can be both specific and nonspecific. Chronic abuse can be signaled by the return of anxiety, insomnia, anorexia, headaches, and weakness. Changes in appearance and behavior that affect relationships and performance at work can be some of the nonspecific signs.

Addicted individuals feel an intense craving for the drug and higher doses are usually needed to achieve the same effects since tolerance develops very quickly with continued use. Sudden cessation of the drug may cause withdrawal symptoms including shaking, nervousness, agitation, insomnia, vomiting, fast heartbeat, sweating, hallucination and confusion. Recovery from these addictions should not be attempted alone. Withdrawal from abuse of benzodiazepines may cause life-threatening complications. Withdrawal symptoms resulting from use of very high doses of benzodiazepines are even comparable to those experienced by alcoholics when they stop drinking alcohol. The first step in overcoming an addiction to any benzodiazepine is to undergo detoxification under strict medical supervision. The dosage of benzodiazepine must be gradually lowered over time. During this time, psychological counseling may be helpful, as well as cognitive-behavioral therapy, which focuses on changing a patient's thinking, expectations, and behavior and increasing his or her skills for coping with the everyday stresses in life.

References

1. Blachford S.L. and Krapp K. eds. Drugs and Controlled Substances Information for Students, Detroit:Thomson Gale, 2003.Drummond, Edward H. The Complete Guide to Psychiatric
2. Olson K.R. ed. Poisoning & Drug Overdose,4th ed. New York: Lange Medical Books, 2004.
3. Drummond, Edward H. The Complete Guide to Psychiatric Drugs: Straight Talk for Best Results. New York: John Wiley &
Sons, Inc., 2000.
4. Emmett D. and Nice G. Understanding Street Drugs. 2d ed. London: Jessica Kingsley Publishers, 2006.