Benzodiazepine

What Kind of Drug Is It?

Benzodiazepines (pronounced ben-zoh-die-AZ-uh-peens) are depressants that relieve anxiety. Their names are easy to recognize because many of them end in the suffix "-am." Some common benzodiazepines are alprazolam, diazepam, and lorazepam. Benzodiazepines are only available legally with a doctor's prescription.

A number of medical terms apply to benzodiazepines. Just like alcohol and barbiturates, benzodiazepines are classified as depressants because they slow down both the mind and the body. They are also considered sedative-hypnotic agents and tranquilizers because they reduce anxiety and promote sleep. Benzodiazepines can be addicting.

Overview

Benzodiazepines are widely prescribed in the treatment of anxiety disorders, sleep disorders, and seizure conditions. They calm down users by acting on the brain to lower anxiety levels, relax muscles, and bring on sleep. Benzodiazepines were first used in the late 1950s. By the 1960s, physicians were regularly prescribing them to patients in place of barbiturates. Barbiturates, another class of depressants, can slow the breathing center of the brain to dangerously low levels. Benzodiazepines have less of an effect on breathing than barbiturates and are therefore considered safer. In addition, benzodiazepines are less likely to lead to death in cases of overdose.

Official Drug Name: Alprazolam (al-PRAZZ-oh-lam; Xanax), chlordiazepoxide (klor-dye-az-uh-POKS-ide; Librium), clonazepam (kloh-NAZZuh-pam; Klonopin), clorazepate (klor-AZZ-uh-pate; Tranxene), diazepam (dye-AZZ-uh-pam; Valium), flurazepam (flor-AZZ-uh-pam; Dalmane), flunitrazepam (Rohypnol), halazepam (huh-LAZZ-uh-pam; Paxipam), lorazepam (lorr-AZZ-uh-pam; Ativan), midazolam (Versed), oxazepam (oks-AZZ-uh-pam; Serax), prazepam (PRAZZ-uh-pam; Centrax), quazepam (KWAY-zuh-pam; Doral), temazepam (tuh-MAZZ-uh-pam; Restoril), triazolam (try-AY-zoe-lam; Halcion)

Also Known As: Benzos, tranks, downers

Drug Classifications: Schedule IV, except for flunitrazepam (Rohypnol), which is a Schedule III drug; depressant

The likelihood of addiction among benzodiazepine users did not become an issue until several years after their introduction. When taken for a limited amount of time in doctor-prescribed doses, benzodiazepines are generally quite safe. Problems develop when they are taken for more than several months or in larger-thanrecommended doses. Psychological and physical dependence on benzodiazepines can actually occur within a matter of weeks. It has also been reported that benzodiazepine abusers usually combine their "benzos" with other drugs or alcohol. These combinations can lead to very serious physical consequences, including slowed breathing, coma, and even death.

About fifty different kinds of benzodiazepines were being used throughout the world in 2005. However, only fifteen of these have been approved for use in the United States by the Food and Drug Administration (FDA). According to The Pill Book, four of the top seventy-five prescriptions written by U.S. doctors in 2003 were for benzodiazepines:

• alprazolam (Xanax) ranked 12th
• lorazepam (Ativan) ranked 32nd
• clonazepam (Klonopin) ranked 52nd
• diazepam (Valium) ranked 68th

Of these benzodiazepines, alprazolam was the most frequently abused in the United States in the early 2000s. This likely occurs because it acts so quickly—within twenty to thirty minutes. As Lance P. Longo and Brian Johnson, writing in American Family Physician, put it, "drugs that work immediately tend to be addictive."

Drug companies classify benzodiazepines according to the length of time it takes for them to begin working. The ultra-short acting benzodiazepines kick in almost immediately and are mainly used in a hospital setting as a form of anesthesia. Two common ultra-short acting benzodiazepines are midazolam (Versed) and triazolam (Halcion). The short-acting benzodiazepines typically begin working in less than half an hour. These are among the most commonly abused drugs and include alprazolam (Xanax) and lorazepam (Ativan). The long-acting benzodiazepines, such as chlordiazepoxide (Librium) and diazepam (Valium), take a longer time to produce effects.

The strongest benzodiazepines, known as high-potency benzodiazepines, include alprazolam, lorazepam, triazolam, and clonazepam. Among the less powerful, or low-potency, benzodiazepines are chlordiazepoxide, clorazepate, diazepam, and flurazepam.

"Mother's Little Helper"

Historically, tranquilizers were not the drug of choice among the biggest drug users of the 1960s. College students, hippies, and concertgoing youths of that decade were more likely to experiment with hallucinogenic drugs. Benzodiazepines and minor tranquilizers were associated more with stay-at-home moms. Their practice of taking Valium—the "little yellow pill"—was widespread in the United States and the United Kingdom during this time. The Rolling Stones recorded a song in 1966 called "Mother's Little Helper" about this trend. As noted on CNN.com, the Stones sang: "Mother needs something today to calm her down / And though she's not really ill, There's a little yellow pill / She goes running for the shelter of a mother's little helper.…"

It is estimated that in the 1970s, as many as 30 million women were taking minor tranquilizers. "In promoting these drugs, the manufacturers portrayed stresses of everyday life as disease states treatable by prescribing their products," explained Andrew Weil and Winifred Rosen in From Chocolate to Morphine. Some advertisements "suggested giving tranquilizers to harried mothers and bored housewives." One particular ad aimed at physicians suggested they carry syringes of injectable diazepam "ready to use, when something must be done to calm the patient in emotional crisis." As Weil pointed out, ads like these always seemed to feature pictures of women as emotionally distressed patients in need of help. Psychiatrists were freely prescribing these minor tranquilizers to women with little regard of their potential for addiction.

What Is It Made Of?

Benzodiazepines consist of chemical substances known as amines. All benzodiazepines are produced in laboratories. Like the other amines, they are derived from ammonia, a gas that consists of one molecule of nitrogen and three molecules of hydrogen.

How Is It Taken?

Benzodiazepines are usually taken in capsule or tablet form, but some are available as an injectable solution. The tablets are typically pastel shades of yellow, green, or blue. Some users dissolve the pills in water, mix them with other drugs, and then inject them directly into a vein.

Are There Any Medical Reasons for Taking This Substance?

Physicians use benzodiazepines in the treatment of many anxiety disorders. For example, they are used to treat panic attacks, which are unexpected episodes of severe anxiety that can cause physical symptoms such as shortness of breath, dizziness, sweating, and shaking. The drugs also help people suffering from post-traumatic stress disorder (PTSD), an illness that can occur after someone experiences or witnesses a life-threatening event such as a serious accident, violent assault, or terrorist attack. PTSD symptoms include reliving the experience through nightmares and flashbacks, having problems sleeping, and feeling detached from reality.

Benzodiazepines also help with obsessive-compulsive disorder (OCD), an anxiety disorder that causes people to dwell on unwanted thoughts, act on unusual urges, and perform repetitive rituals such as frequent hand washing. Benzodiazepines may also be used to relieve tension, agitation, insomnia, muscles spasms, and epileptic seizures.

Patients undergoing surgery, dental procedures, diagnostic studies, and cancer treatments are sometimes given benzodiazepines to help reduce their fear and anxiety. In addition, benzodiazepines may be prescribed for alcoholics and addicts undergoing the detoxification process. When used under strict medical supervision, these drugs can lessen the symptoms of withdrawal that occur as the user cuts back on the amount of a drug being taken until use can be discontinued entirely.

Usage Trends

Benzodiazepines are very commonly prescribed, but they are supposed to be used only for brief periods of time. Benzodiazepine drugs have a number of genuine medical uses, but they are most frequently prescribed to relieve anxiety and fear. According to the American Psychiatric Association (APA), approximately "8 percent of all adults have suffered from a phobia, panic disorder or other anxiety disorder" during any given six-month period. "For millions of Americans, anxiety disorders are disruptive, debilitating and often the reason for loss of job and serious problems in family relationships."

Treating Anxiety

Anxiety disorders are sometimes controllable without drugs. Patients are often able to reduce their anxiety to manageable levels through weekly "talk therapy" sessions with trained psychotherapists. One type of psychotherapy, called cognitive-behavioral therapy (cbt), has a very high success rate. Cognitive-behavioral therapy helps patients change their outlook on life and recast their negative feelings into positive ones.

In certain cases, however, therapy is not enough. Patients may require medication to control their symptoms. Psychiatrists often prescribe benzodiazepines to such patients. According to the APA, these drugs "relieve the fear, help end the physical symptoms such as pounding heart and shortness of breath, and give people a greater sense of control." Along with that greater sense of control comes the ability to recognize and "reduce the stress that can trigger anxiety."

Benzodiazepines are most commonly prescribed for women and elderly patients. Four out of five people who experience panic attacks are female. Elderly patients are commonly diagnosed with conditions such as insomnia and depression. These conditions respond well to treatment with certain benzodiazepines. But long-term use of these drugs among the elderly increases the likelihood of these patients developing a physical dependence on benzodiazepines.

In one study cited by Mental Health Weekly, 60 percent of older women taking benzodiazepines by prescription were on the drugs for more than four months. That time period is longer than recommended. In addition, the National Institute on Drug Abuse (NIDA) reported in its "Prescription Drugs: Abuse and Addiction" that "elderly persons who take benzodiazepines are at increased risk for falls that cause hip and thigh fractures, as well as for vehicle accidents."

Part of the Multi-Drug Mix

Among drug abusers, benzodiazepines are hardly ever used alone. The White House's drug policy publication "Pulse Check" revealed that multi-drug use "increased steadily" between 1993 and 2003. About 80 percent of benzodiazepine abuse occurs in people who regularly abuse other drugs. This has led to "increased complications for drug treatment," noted the "Pulse Check" report, because "it is hard to determine what clients are using."

illicit drug users report that benzodiazepines increase and lengthen the high they get with other drugs. Heavy drinkers have reported that benzodiazepines enhance the effects of alcohol. These drugs can also ease the process of "coming down" from a stimulant high. So, many multi-drug abusers use it as part of their regular drug mix.

Reading up on Rohypnol

Flunitrazepam (Rohypnol) is an extremely powerful and fast-acting benzodiazepine. The drug began receiving a lot of attention in the mid-1990s, especially on college campuses because of its use as a "date rape" drug. Flunitrazepam is one of the drugs, along with ecstasy (MDMA), used by teens and young adults as part of the nightclub, bar, or "rave" scene. Raves are wild overnight dance parties that usually involve huge crowds of people, loud techno music, and illegal drug use.

Flunitrazepam is also known by the brand name Rohypnol and the street names roofies, R2, Roche, roofinol, rope, rophies, forget-me pill, and Mexican valium. It comes in the form of a small, white tablet with "Roche" on one side and a "1" or "2" in a circle on the other side. The numbers indicate a 1-milligram or 2-milligram dosage. It is usually taken by mouth, often combined with alcohol. Or, it is sometimes snorted after the user crushes the tablets.

The effects of Rohypnol include sedation, muscle relaxation, and anxiety reduction. Its sedative effects are said to be seven to ten times stronger than diazepam (Valium). Because it is tasteless and odorless, flunitrazepam is hard to detect in beverages. After taking this drug, users begin to feel intoxicated rather quickly. The "drunken" feelings soon turn to extreme sleepiness. Speech becomes slurred, and judgment is most definitely impaired. Partial amnesia is a common effect, as well. For this reason, flunitrazepam has been used in date rape.

Victims of date rape are usually unable to remember the assault or identify their attacker because Rohypnol affects one's memory. Rohypnol begins working within minutes of being consumed. Its effects can last up to eight hours. Deep sedation, respiratory distress, and daylong blackouts are some of the more serious possible effects of Rohypnol. In high doses, flunitrazepam can kill.

Rohypnol has never been approved for use in the United States. It is smuggled in from other countries in Europe, Central America, and South America. The U.S. Congress passed the Drug-Induced Rape Prevention and Punishment Act of 1996. This legislation increased the federal penalties for individuals using any controlled substance to aid them in sexual assault. The law makes it a crime to give others a controlled substance without their knowledge or with the intent to commit a violent crime against them. (A separate entry on Rohypnol is available in this encyclopedia.)

Abuse of benzodiazepines is especially high among heroin, cocaine, and methadone abusers. (A separate entry on each of these drugs is available in this encyclopedia.) According to S. Pirzada Sattar and Subhash Bhatia in an article for Current Psychiatry Online, nearly half of all intravenous (v) drug abusers also take benzodiazepines. However, "even patients who begin taking benzodiazepines for legitimate reasons may end up abusing them."

Who's Using Benzodiazepines?

Patterns of benzodiazepine use in America have been documented in two long-term surveys. One is the Monitoring the Future (MTF) study conducted by the University of Michigan (U of M) and sponsored by research grants from NIDA. The second is the National Survey on Drug Use and Health (NSDUH), previously called the National Household Survey on Drug Abuse or NHSDA. It is conducted by the Substance Abuse and Mental Health Services Administration (SAMHSA), a division of the U.S. Department of Health and Human Services.

The results of the 2004 MTF study were released to the public on December 21, 2004. Since 1991, U of M has tracked patterns of drug use and attitudes toward drugs among students in the eighth, tenth, and twelfth grades. (Prior to that, from 1975 to 1990, the MTF survey was limited to twelfth graders.) The 2004 MTF survey revealed that the use of tranquilizers and sedatives remained relatively "stable among all grades." About 2.5 percent of eighth graders, 5.1 percent of tenth graders, and 7.3 percent of high school seniors reported using drugs like Xanax between 2003 and 2004.

SAMHSA's 2003 NSDUH was broader than the MTF survey. The NSDUH traces drug use in the United States among people of all ages, not just among eighth, tenth, and twelfth graders. The NSDUH obtains information about nine different categories of illicit drug use. One of those categories includes the nonmedical use of prescription-type pain relievers, tranquilizers, stimulants, and sedatives.

Typical Users

Benzodiazepine users can be young or old, male or female. Illicit users—individuals who were not prescribed the drug for a medical reason—typically range in age from their late teens to early thirties. About two-thirds of these users are male.

NSDUH reports combine the four prescription-type drug groups into a category referred to as "any psychotherapeutics" (SY-koh-ther-uh-PYOO-tiks). Numerous drugs are covered by this category. All of them are available through prescriptions and sometimes illegally "on the street." Over-the-counter drugs and legitimate uses of prescription drugs are not included in the NSDUH report. Respondents are asked to report only uses of drugs that were not prescribed for them or drugs they took only for the experience or feeling they caused.

The results show that a number of Americans became "new users" of psychotherapeutic drugs in 2002. Roughly 1.2 million people began using tranquilizers, and 225,000 began using sedatives. Among fifteen benzodiazepines, the nonmedical use of two specific drugs—alprazolam (Xanax) and lorazepam (Ativan)—rose the most between 2002 and 2003, from 3.5 percent to 4 percent of those surveyed. Use among twelve to seventeen year olds was unchanged, reflecting the same trend as the MTF survey. The biggest jump was seen in users who were slightly older, age eighteen to twenty-five. From 2002 to 2003, usage in that particular age group increased from 6.7 to 7.5 percent.

In Canada, benzodiazepine use is tracked by the Centre for Addiction and Mental Health (CAMH). The CAMH publishes a series of leaflets on drugs under the title "Do You Know. … " The "Do You Know… Benzodiazepines" leaflet states that "approximately 10 percent of Canadians report using a benzodiazepine at least once a year, with one in ten of these people continuing use regularly for more than a year."

Effects on the Body

Benzodiazepines act on the area of the brain that controls emotions. They do this by boosting the effects of a neurotransmitter called gamma-aminobutyric acid (GABA). GABA receptor sites are especially numerous on cells in the part of the brain responsible for fear and worrying. Benzodiazepines work by increasing GABA activity. Higher levels of GABA activity help block feelings of tension and anxiety. The result is a calming effect. Some benzodiazepines bind more tightly to GABA receptors than others, causing more intense sedation.

Benzodiazepines are designed to produce feelings of relaxation and an increased sense of well-being in the user. But, along with reducing anxiety, these drugs decrease emotional reactions, mental alertness, and attention span. Common side effects of benzodiazepine use include confusion, drowsiness, loss of coordination, dizziness, and light-headedness. More serious side effects caused by these drugs are rare but can occur. They include outbursts of anger, severe depression, hallucinations, muscle weakness, extreme tiredness, loss of memory, skin rashes, itching, fever and chills, and sores in the throat or mouth.

High doses of benzodiazepines lead to symptoms similar to those caused by excessive use of barbiturates or alcohol. These include slurred speech, impaired memory, slowed breathing, and lowered blood pressure. Although overdosing on benzodiazepines alone is not likely, it has occurred. In these cases, the patients' rate of breathing and blood pressure dropped so low that they went into a coma and eventually died.

Use Interferes with Learning and Memory

Benzodiazepines seem to interfere with memory formation and learning. They "can prevent the brain from recording and adapting to new information," explained Cynthia Kuhn and her coauthors in Buzzed: The Straight Facts about the Most Used and Abused Drugs from Alcohol to Ecstasy. "Someone who needs to learn new information should never use these drugs and expect to do so to their full potential."

For example, college students might take benzodiazepines while studying. They might use the drugs in an attempt to relax or to get a good night's sleep. However, such drugs can make it difficult for students to recall the information they need on exam day. Impaired memory is limited to events that occur during the time the drugs are being used. When the dosage wears off, new learning and memory formation become possible again.

Because they decrease mental alertness, benzodiazepines should never be used when driving or operating heavy machinery. "Benzodiazepines slow reaction time and impair driving skills, increasing the risk of motor vehicles crashes in patients who are taking [them]," explained Longo and Johnson. In addition, benzodiazepines should not be taken by pregnant women or by people suffering from lung, kidney, or liver disease.

Addiction and Withdrawal

Benzodiazepines are addictive substances. Regular use of any benzodiazepine can lead to physical and psychological dependence in as little as four to six weeks. According to a 2002 Mental Health Weekly article, taking Xanax "for more than eight weeks carries a high

risk of dependency." Both psychologically and physically addicted users may experience cravings for the drug, but those with physical addictions will actually experience withdrawal symptoms if they suddenly stop taking benzodiazepines. In other words, they will become ill if they don't get the drug into their systems. Withdrawal symptoms can be quite serious and range from insomnia, nervousness, irritability, and nausea, to tremors, seizures, and even hallucinations.

Reactions with Other Drugs or Substances

When taken with other depressants such as alcohol or barbiturates, benzodiazepines can be extremely dangerous. The combined effects of two or more depressants can greatly lower blood pressure and reduce a user's ability to breathe. This, in turn, can lead to coma and death. Use of benzodiazepines with meperidine, oxycodone, codeine, or morphine can be deadly as well. (Entries on each of these drugs are available in this encyclopedia).

Treatment for Habitual Users

The potential for addiction to benzodiazepines is very real. That potential is even greater among certain segments of the population, especially those undergoing treatment for substance abuse. "Among psychiatric patients," wrote Sattar and Bhatia, "substance abusers are most likely to abuse benzodiazepines and become addicted to them." Multiple addictions are complicated. Users should seek professional help when trying to stop using the drug.

The withdrawal process can take weeks or even months and requires a combination of physical and psychological care. Benzodiazepine abusers must undergo the process of detoxification under strict medical supervision. During this time, the dosage of the drug is lowered gradually, and eventually use is phased out completely. Cognitive-behavioral therapy helps provide habitual users with the support they need to kick their habit. This type of psychotherapy focuses on increasing a patient's skills for coping with the everyday stresses in life.

Unwanted Side Effects

Interesting evidence has surfaced about the effects of benzodiazepines on some patients. Although such drugs are routinely prescribed to treat the anxiety that comes with depression, benzodiazepines—especially when taken in high doses—may actually increase the risk of depression. This theory was reinforced in 2004, when a study was conducted on soldiers returning home from war. War, terrorist attacks, and other life-threatening events can trigger post-traumatic stress disorder (PTSD) in people who have experienced these events firsthand. A Harvard Medical School doctor noted in Newsweek that "anxiety-muting benzodiazepines such as lorazepam and clonazepam may actually raise the risk of chronic PTSD if taken continuously." The reasons for this unwanted side effect were still being studied in 2005.

Consequences

"It is dangerous to combine any sedative, including benzodiazepines, with anything else that makes a person sleepy," stated Kuhn. Mental Health Weekly reported that in 2001, bad reactions to Xanax and other benzodiazepines were responsible for a high percentage of prescription drug-related emergency room visits. The use and abuse of benzodiazepines can impair decision-making, decrease learning skills, and bring on aggression. Each of these factors can have a significant effect on an individual's educational, social, and workplace environments.

The Law

"The nonmedical use or abuse of prescription drugs remains a serious public health concern," wrote the NIDA director in his introduction to "Prescription Drugs: Abuse and Addiction." Medical prescriptions are the primary source of benzodiazepines for abusers, but some of these prescriptions are obtained illegally. Benzodiazepine addicts often use a practice known as "doctor shopping" to keep up with their addiction. They switch doctors and visit emergency rooms regularly in the hopes of getting multiple prescriptions for benzodiazepines. The doctors used in this scheme are usually unaware that another physician has already prescribed the same drugs for the patient.

Writing fake prescriptions on stolen prescription pads is a common practice used to obtain prescription drugs. Another means of getting prescription drugs such as benzodiazepines is by buying the drug from a patient who was legitimately prescribed the medication. These "legitimate" patients can be friends, parents, relatives, or even people on the street offering their pills in exchange for money.

ER Visits

The Drug Abuse Warning Network (DAWN) collects data on drug-related hospital emergency room (ER) visits throughout the United States. ER trips resulting from benzodiazepine abuse numbered more than 100,000 in 2002, an increase of 41 percent since 1995. Complete results of the DAWN report can be found at http://www.oas.samhsa.gov.

Regardless of how the drugs are obtained, it is against the law to possess or use controlled substances such as benzodiazepines without a doctor's prescription. Selling or distributing benzodiazepines to others is a more serious offense. Physicians who write fraudulent prescriptions are also subject to various legal consequences. These include felony convictions and the possible loss of their medical licenses.

For More Information

Books

Gahlinger, Paul M. Illegal Drugs: A Complete Guide to Their History, Chemistry, Use, and Abuse. Las Vegas, NV: Sagebrush Press, 2001.

Kuhn, Cynthia, Scott Swartzwelder, Wilkie Wilson, and others. Buzzed: The Straight Facts about the Most Used and Abused Drugs from Alcohol to Ecstasy, 2nd ed. New York: W.W. Norton, 2003.

Preston, John D., John H. O'Neal, and Mary C. Talaga. Consumer Guide to Psychiatric Drugs. New York: New Harbinger Publishers, 1998.

Schull, Patricia Dwyer. Nursing Spectrum Drug Handbook. King of Prussia, PA: Nursing Spectrum, 2005.

Silverman, Harold M. The Pill Book, 11th ed. New York: Bantam, 2004.

Weil, Andrew, and Winifred Rosen. From Chocolate to Morphine. New York: Houghton Mifflin, 1993, rev. 2004.

Periodicals

"Anti-Anxiety Drugs Being Overprescribed for Medicaid SA Patients." Mental Health Weekly (January 19, 2004): p. 3.

"ER Visits Involving Anti-Anxiety Drugs Increase." Mental Health Weekly (August 30, 2004): p. 5.

Longo, Lance P., and Brian Johnson. "Addiction: Part I. Benzodiazepines—Side Effects, Abuse Risk, and Alternatives." American Family Physician (April 1, 2000): pp. 2121-2131.

Shalev, Arieh Y., and Michael Craig Miller. "To Heal a Shattered Soul." Newsweek (December 6, 2004): p. 70.

"Xanax May Be Addictive at Prescribed Doses." Mental Health Weekly (October 28, 2002): p. 8.

Web Sites

"2003 National Survey on Drug Use and Health (NSDUH)." U.S. Department of Health and Human Services, Substance Abuse and Mental Health Services Administration.http://www.oas.samhsa.gov/nhsda.htm (accessed June 30, 2005).

"Do You Know… Benzodiazepines." Centre for Addiction and Mental Health.http://www.camh.net/pdf/benzodiazepines_dyk.pdf (accessed June 30, 2005).

Kennedy, Bruce. "The Tranquilizing of America." CNN.com.http://www.cnn.com/SPECIALS/1999/century/episodes/06/currents (accessed August 8, 2005).

Monitoring the Future.http://www.monitoringthefuture.org/ and http://www.nida.nih.gov/Newsroom/04/2004MTFDrug.pdf (both accessed June 30, 2005).

"Prescription Drugs: Abuse and Addiction." National Institute on Drug Abuse (NIDA) Research Report Series.http://www.drugabuse.gov/ResearchReports/Prescription/ (accessed June 30, 2005).

"Psychiatric Medications." American Psychiatric Association (APA).http://www.psych.org/public_info/medication.cfm (accessed June 30, 2005).

"Pulse Check: Drug Markets and Chronic Users in 25 of America's Largest Cities." Executive Office of the President, Office of National Drug Control Policy.http://www.whitehousedrugpolicy.gov/publications/drugfact/pulsechk/january04/january2004.pdf (accessed June 30, 2005).

Sattar, S. Pirzada, and Subhash Bhatia. "Benzodiazepines for Substance Abusers: Yes or No?" Current Psychiatry Online.http://www.currentpsychiatry.com (accessed February 25, 2005).

See also: Alcohol; Antidepressants; Barbiturates; Ecstasy (MDMA); Rohypnol