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Date: Oct. 1, 2016
Publisher: Gale, a Cengage Company
Document Type: Drug overview; Topic overview
Length: 4,191 words

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Official Names: Ketamine (KEE-tuh-meen or KETT-uh-meen), ketamine hydrochloride (HIGH-droh-KLOR-ide); brand names include Ketaset and Ketalar
Street Names: Blind squid, cat valium, honey oil, jet, K, ket, kit kat, Special K, vitamin K
Drug Classification: Schedule III, hallucinogen

What Kind of Drug Is It?

Ketamine is a general anesthetic (pronounced ann-ess-THET-ik), which is a substance used to deaden pain. General anesthetics differ from local anesthetics in two key ways: 1) general anesthetics affect the entire body rather than just a specific body part; and 2) in addition to causing a loss of sensation, they bring on a loss of consciousness.

Ketamine is very similar in structure to another anesthetic called phencyclidine (fenn-SY-kluh-deen), also known as PCP. However, it is not as powerful. (An entry on PCP is available in this encyclopedia.) Both ketamine and PCP are known as dissociative anesthetics because of the mind-altering side effects they produce.


The anesthetic ketamine was developed as an alternative to PCP for use in humans. Ketamine, a fast-acting drug, was discovered by Dr. Calvin Stevens of Wayne State University in Detroit, Michigan, in the early 1960s. It was considered a breakthrough drug in the field of anesthesia because of its ability to bring on sleep, relieve pain, and produce short-term memory loss in surgical patients. In addition, its anesthetic actions would not depress, or slow down, the breathing process. Doctors enthusiastically embraced the use of ketamine in the operating room, thinking the drug would make their patients feel more relaxed and comfortable when they awoke from surgery.

Ketamine was first used on patients in 1970. The U.S. military even used it as a battlefield anesthetic during the Vietnam war (1954-1975). However, with the increased use of ketamine came more and more reports of its unusual side effects. Many people who were given the anesthetic in prescribed doses in a medical setting experienced bizarre hallucinations when they began regaining consciousness. Some claimed that they met up with dead relatives and friends, talked to angels, and had out-of-body experiences. As a result, the medical use of ketamine on humans dropped considerably.

Ketamine use has also been linked to brain damage. As of 2005, ketamine was used mainly by veterinarians on animals as an intravenous or intramuscular anesthetic.

From Experimental Hallucinogen to Club Drug

The use of hallucinogens--drugs that can produce hallucinations and distort reality--skyrocketed in the 1970s. Hallucinogens such as LSD (lysergic acid diethylamide) became extremely popular during this era of social and political upheaval. (A separate entry on LSD is available in this encyclopedia.) Stories about ketamine's effects soon captured the interest of experimental drug users. Ketamine use produces "trips," which are basically extended hallucinations of an intense and usually very visual nature. Ketamine trips are similar to those of other, better-known hallucinogenic drugs. However, ketamine--widely known as Special K--never really became a mainstream drug in the 1970s.

Later, with the emergence of the rave scene in the late 1980s and early 1990s, ketamine gradually resurfaced as a club drug. Though used much less frequently than ecstasy (MDMA) or methamphetamine, ketamine became increasingly popular among young people in the middle and late 1990s. (Entries on ecstasy and methamphetamine are available in this encyclopedia.) According to "An Overview of Club Drugs: Drug Intelligence Brief," published by the U.S. Drug Enforcement Administration (DEA), "a significant number of veterinary clinics" were being robbed around that time "specifically for their ketamine stock." These robberies came about because ketamine is a difficult drug to synthesize, or make in a laboratory. Some users found that it was actually easier to steal it than it was to make it.

In 1995, ketamine was added to the DEA's Emerging Drugs List, indicating that it was recognized as a threatening new substance among drug users. Four years later, on August 12, 1999, ketamine became illegal in the United States. It is considered a Schedule III drug according to the terms of the Controlled Substances Act of 1970.

What Is It Made Of?

Ketamine belongs to the same family of drugs as 1) dextromethorphan (DXM), which is found in some brands of over-the-counter cough syrup; 2) nitrous oxide, better known as "whippets," for the metal whipped cream chargers in which the gas is packaged; and 3) PCP, also known as angel dust. (Entries on these drugs are available in this encyclopedia.)

Ketamine is a synthetic drug, meaning that it does not occur naturally but is manufactured in a lab from chemicals. It is most commonly used in its hydrochloride form. The chemical formula for ketamine hydrochloride is C13H16ClNO·HCl. The chemical structure and effects of ketamine are similar to those of PCP. However, PCP is a longer lasting and more powerful drug than ketamine.

How Is It Taken?

Ketamine is snorted, smoked, or dissolved in water. The liquid form is swallowed or injected directly into a vein or muscle. When used by physicians or veterinarians as an anesthetic, ketamine comes in liquid form and is packaged in small glass vials. This liquid can be returned to a dry form by heating or "cooking" it. The "baked" drug is then crushed into a powder. Powdered ketamine is snorted through the nose in "bumps" (similar to "lines" of cocaine). It is also sprinkled on marijuana or tobacco and rolled into a homemade cigarette. In the United States, a 20-milligram unit of ketamine typically sells for about $25.

Users sometimes mix ketamine with a stimulant like cocaine or methamphetamine. When taken together, this combination is referred to as "trail mix." Sometimes, drug dealers "cut" ketamine with other substances to yield a bigger batch and make more money. Users can never be sure of the drug's purity. Samples of seized ketamine have included substances such as amphetamines, heroin, PCP, caffeine, and other fillers. Ketamine has also been compressed into pills or loaded into capsules and sold as other illegal drugs, including ecstasy. (Entries on cocaine, amphetamines, caffeine, ecstasy (MDMA), heroin, methamphetamine, and PCP are included in this encyclopedia.)

Are There Any Medical Reasons for Taking This Substance?

Ketamine has been approved for both human and animal use as an injectable anesthetic in medical settings since 1970. About 90 percent of the ketamine sold legally in the United States is intended for veterinary use. Its use in humans is usually limited to children and elderly patients. Individuals in both of these age groups seem to tolerate ketamine better than other general anesthetics. However, tranquilizers must be administered in combination with ketamine to keep these patients from experiencing hallucinations. (An entry on tranquilizers is included in this encyclopedia.)

Usage Trends

Before the late 1980s, ketamine was not widely abused. Its use was not considered extensive enough to prompt action by the U.S. Drug Enforcement Administration (DEA) until the 1990s.

The 2004 "Pulse Check" report released by the White House's Office of National Drug Control Policy stated that "young adults working independently are the primary dealers of ketamine, which they obtain through burglaries of veterinary clinics." Since the late 1990s, vets have been urged to install burglar alarms in their offices and lock up their ketamine supplies. Closer monitoring of ketamine supplies has made it more difficult to obtain.

Club Drugs, Raves, and "Date Rape"

An increase in ketamine use occurred with the growth of the rave culture beginning in the late 1980s and early 1990s. According to the Substance Abuse and Mental Health Services Administration (SAMHSA), a division of the U.S. Department of Health and Human Services, the typical American club drug user is between eighteen and twenty-five years old. Users in Australia and the United Kingdom are around the same age. This population dominates the club drug market and has made ecstasy and other so-called designer drugs some of the fastest-growing drugs of choice on the club circuit. (An entry on designer drugs is available in this encyclopedia.) Because of its unpleasant side effects, however, ketamine has never been as popular as ecstasy among rave attendees.

Like other club drugs such as GHB and Rohypnol, ketamine has been used as a "date-rape" drug. Liquid ketamine is "odorless and tasteless," warns the Partnership for a Drug-Free America, "so it can be added to beverages without being detected." In addition, it causes memory loss. Victims of ketamine-related sexual assaults may find it impossible to identify their attackers. (Entries on GHB and Rohypnol are also available in this encyclopedia.)

Usage Patterns Begin to Decline

The Drug Abuse Warning Network (DAWN) tracks hospital emergency department (ED) visits caused by drug use. From the 1980s through the first decade of the twenty first century, the number of ED visits attributable to the misuse and abuse of ketamine remained low and relatively constant, ranging from 250 in 2002 to 303 in 2005. It then began to climb rapidly, reaching 529 in 2009, 915 in 2010, and 1,550 in 2011, the last year for which data are available.

Additional data about the misuse and abuse of ketamine by teenagers are available from the Monitoring the Future (MTF) study conducted by the Institute for Social Research (ISR) at the University of Michigan. According to the 2014 MTF report, 1.5 percent of twelfth graders surveyed said that they had used ketamine for non-medical purposes in the year preceding the survey. That number had been dropping slowly since 2000, the first year the question was asked by MTF, when it was 2.5 percent. Eighth and tenth graders were also asked about ketamine use in the 2000 through 2011 surveys, after which the question was dropped for these two age groups. Ketamine use was lower for both younger age groups in 2011 than for twelfth graders, 0.8 percent and 1.2 percent, respectively, compared to 1.7 percent. Decreases in use were also reported for both eighth graders and tenth graders from 2000 rates (1.8 percent and 2.1 percent, respectively).

Ketamine abuse is not solely an American problem. In its 2015 World Drug Report, the United Nations Office on Drugs and Crime found that 58 countries worldwide had reported increasing concerns about the misuse and abuse of ketamine.

Effects on the Body

Ketamine is a dissociative anesthetic. It produces all of the symptoms associated with anesthesia, including the inability to control movement, register pain, or recall memories. Common side effects of ketamine use include confusion; dizziness; tiredness; loss of muscle control; numbness; intoxication, the loss of physical or mental control; and amnesia

Ketamine interferes with the brain's ability to receive, process, and send out certain signals. This distorts users' perceptions of sights, sounds, space, and time. Ketamine also brings on feelings of detachment, making users feel removed from their physical bodies. The drug's effects occur shortly after it is taken, sometimes causing users to collapse suddenly. After using ketamine once, many people will not use it again.

A Place Called "K-Land"

A typical ketamine trip begins with a feeling of numbness all over the body. At low doses, users generally become somewhat disoriented, lose their sense of balance, and find it difficult to walk. Users then experience altered vision, muffled hearing, and a floating sensation as they enter a dreamy state known as "K-Land." In Designer Drugs, M. Foster Olive noted that "the perception of colors and music is enhanced" in the "K-Land" phase, and users may see "walls and carpets glowing different colors [and] ceilings turning to liquid." Some ketamine users claim that while in this relaxed state, they gain insights into their own personalities, the people they know, and the workings of the universe.

At higher doses, ketamine increases the sense of disconnection between the mind and the body. Users feel as if they are looking down at themselves from some higher place. These so-called "out-of-body experiences" are sometimes religious in nature. Some users claim they have seen visions of angels after taking ketamine. But the hallucinations associated with ketamine are not always pleasant.

The Terror of a "K-Hole"

Heavy use of ketamine intensifies the drug's effects dramatically. The user's judgment becomes extremely impaired, and vision becomes totally distorted. Auditory hallucinations may begin to appear as well. (Ongoing humming or buzzing sounds are the most common.) Some users find it very difficult to move or speak. They may also feel as if time has stopped completely.

Users who have experienced these symptoms run the risk of landing in a "K-Hole." The authors of the NIDA research report titled "Hallucinogens and Dissociative Drugs" describe the "K-Hole" experience as "a terrifying feeling of almost complete sensory detachment that is likened to a near-death experience." The "K-Hole" generates extremely vivid and often frightening hallucinations in users. These individuals may also experience nausea, vomiting, convulsions, delirium, respiratory depression, and a loss of consciousness. Ketamine users who have eaten or consumed alcohol before taking high doses of the drug are likely to vomit and run the risk of choking to death.

The "K-Hole" is usually reached after snorting 100 milligrams of ketamine. When injected, however, lower doses of the drug can bring on "K-Hole" terrors. After coming out of a "K-Hole," users may not remember who they are, where they are, or what happened to them. Such feelings can trigger paranoia (abnormal feelings of suspicion and fear), extreme anger, and violent actions. A ketamine trip can last anywhere from forty-five minutes to several hours. However, according to a Prevention Alert article on ketamine, it usually takes twenty-four to forty-eight hours "before the user feels completely 'normal' again."

Brain Damage and Other Dangers

Hallucinogens interrupt the normal flow of neurotransmitters in the brain. Ketamine has an especially strong effect on the workings of the neurotransmitter glutamate. When the brain's supply of glutamate is blocked, people have difficulty perceiving and responding to changes in their environment.

Dissociative anesthetics like ketamine have been shown to cause brain damage. The DEA noted in "An Overview of Club Drugs" that heavy use of ketamine can bring on long-term memory problems and "cognitive difficulties." (Cognitive refers to intellectual activities.) The types of difficulties most often seen include slurred speech and a decreased attention span.

When used as a general anesthetic and administered by a trained medical professional, ketamine will not interfere with the normal breathing process. When abused, however, the drug can cause severe respiratory depression and an irregular heartbeat.

Women who take any dissociative anesthetic (ketamine, dextromethorphan, or PCP, to name a few) while pregnant expose their developing babies to the drugs' toxic, or poisonous, effects. Children born to women who take ketamine during their pregnancy may suffer severe brain damage.

Reactions with Other Drugs or Substances

People who attend raves often take more than one drug at a time, with ketamine as part of the mix. The risks involved in ketamine use are increased when it is taken along with alcohol, barbiturates, or other drugs that cause respiratory depression. When the breathing rate and heart rate are slowed to dangerously low levels, the brain cannot get enough oxygen. Permanent brain damage or even death can occur in these cases.

Treatment for Habitual Users

Users of ketamine develop a tolerance to the drug over time. Higher doses increase the likelihood and severity of "K-Hole" experiences. The psychological dependence associated with heavy ketamine use can be quite strong. Continued use of ketamine over extended periods of time can result in marked personality changes in the user.

Long-time ketamine users who want to stop taking the drug usually experience withdrawal symptoms as they begin gradually cutting back on the amount of the drug being taken until it is discontinued entirely. Symptoms of withdrawal include amnesia, slurred speech, difficulty concentrating, and a craving for the drug. Habitual users are likely to benefit from drug treatment programs that include counseling and psychotherapy. Through the help of a trained therapist, psychotherapy uses a variety of techniques to improve a patient's outlook on life.


Ketamine can trigger severe emotional breakdowns in some users. People who suffer from schizophrenia or other mood disorders are at special risk, since hallucinogenic drug use may reactivate mental illnesses that were once under control.

In Designer Drugs, Olive pointed out that ketamine "impairs the user's senses and judgment for up to twenty-four hours after taking the drug, even though the initial trip wears off within an hour or so." As a result, the user loses the ability to drive a car or operate machinery safely. Ketamine is also dangerous because of its painkilling properties. An individual under its influence may sustain a serious injury (such as a burn or a deep cut) without even knowing it. This occurs when the pain center of the brain is blocked.

Data published on NIDA's Epidemiology of Youth Drug Abuse Web site suggest that people who inject ketamine are often young, live in economically depressed urban areas, and have experience dealing drugs. Furthermore, they seem to lack, or ignore, basic knowledge about the dangers of sharing needles with other drug users. Consequently, many young users who inject ketamine run a high risk of contracting HIV (the human immunodeficiency virus), which can lead to AIDS (acquired immunodeficiency syndrome). Likewise, the decrease in inhibitions resulting from ketamine use is a cause for concern. Individuals under the influence of ketamine may engage in unsafe sexual activity. Unprotected sex is the leading cause of HIV transmission.

The Law

On August 12, 1999, the DEA added ketamine to the list of Schedule III drugs. Under the terms of the Controlled Substances Act, Schedule III drugs are approved for medical use. Their recreational use or abuse, however, can lead to dependence. It is illegal to buy or sell ketamine without a prescription in the United States. It cannot be used legally without a prescription.

Penalties for possession of ketamine can result in jail terms and fines. Repeat offenders may receive a prison sentence of up to ten years and a fine of up to $500,000. When ketamine is used by an individual in the commission of another crime, such as rape, the penalties are particularly severe. Any individual who uses ketamine or any other date-rape drug to commit a sexual assault could be sentenced to life in prison.

Ketamine has become a world wide problem, with extensive use in Europe, and more in Asia. In 2007, the United Nations passed that demonstrates its concern regarding abuse of this drug.

Key Terms

dissociative anesthetics
pronounced dih-SOH-shee-uh-tiv; drugs that cause users to feel as if their minds are separated from their bodies
visions or other perceptions of things that are not really present
injected into a vein
injected into a muscle
a wild overnight dance party that typically involves huge crowds of people, loud techno music, and illegal drug use
a chemical compound composed of the elements hydrogen and chlorine, often in the form of a crystallized salt
a substance that increases the activity of a living organism or one of its parts
the loss of memory
a mental disturbance marked by confusion, hallucinations, and difficulty focusing attention and communicating
respiratory depression
a slowed breathing rate; severe cases can cause a person to slip into a coma or even stop breathing entirely
substances that help spread nerve impulses from one nerve cell to another
pronounced bar-BIH-chuh-rits; drugs that act as depressants and are used as sedatives or sleeping pills; also referred to as "downers"
a condition in which higher and higher doses of a drug are needed to produce the original effect or high experienced
psychological dependence
the belief that a person needs to take a certain substance in order to function
a mental disease characterized by a withdrawal from reality and other intellectual and emotional disturbances
inner thoughts that keep people from engaging in certain activities
recreational use
using a drug solely to achieve a high, not to treat a medical condition

John C. Lilly: The Case of the Addicted Physician

The man most closely associated with early ketamine experimentation and research was John C. Lilly (1915-2001). Lilly was an author, educator, and physician who specialized in the field of neurology, the branch of medicine that deals with the study of the brain, the spinal cord, and the nerves of the body. He is remembered for his groundbreaking research on human consciousness. Lilly's studies ranged from tracing the brain's pain and pleasure pathways to exploring the possibilities of human-dolphin communication. The films Altered States (1998) and The Day of the Dolphin (1973) are based on his ideas.

Lilly believed that brain researchers should undergo the same tests and experiences as their patients. His work led to the advanced electronic imaging used in medicine in the early 2000s. In an attempt to discover more about the workings of the brain, Lilly experimented with a variety of mind-altering drugs, including LSD and ketamine. He also invented the isolation tank to see what would happen if a person's senses were not stimulated for a given period of time. Lilly believed that his own experience with the device allowed him to view another reality.

This interest in exploring other realities led Lilly to abuse ketamine for its hallucinogenic effects. In his 1978 autobiography The Scientist, Lilly explains that he began taking ketamine injections to relieve the unbearable pain of his migraine headaches. He notes that he felt transformed by the drug's mind-altering properties. Lilly soon became addicted to ketamine. Within several months, he was injecting the drug several times a day. At the peak of his abuse, he took 50 milligrams of the drug every hour for stretches lasting up to twenty hours.

Did You Know?

Ketamine's effects on users multiply dramatically as the dose is increased, even if the increase is very small. The method by which the drug is taken--whether it is snorted through the nose, swallowed by mouth, or injected into a muscle--also has a lot to do with the effects it will produce.

When snorted, ketamine begins to act anywhere from five to fifteen minutes after it is taken. It can stay in the user's system for up to an hour. Most users who snort ketamine begin to feel its effects after taking about 10 milligrams of the drug. A 30- to 70-milligram dose affects vision, hearing, balance, and muscle coordination. The disconnection between mind and body known as the "dissociative" state typically appears after snorting dosages of 100 to 150 milligrams. Doses at or near 250 milligrams may cause unconsciousness for up to three hours or more.

When swallowed, it takes longer for ketamine to take effect (up to twenty minutes on a full stomach), and the effects of the drug last much longer, from three to six hours or more depending on the dose.

When injected into a muscle, ketamine acts much more quickly--usually in a minute or two. Taking ketamine by injection is extremely dangerous. The risks of accidental death or permanent injury from overdose by injection are greater than with any other method.

In Hot Pursuit of Ketamine Dealers

Seizures of ketamine have been reported worldwide. Between 2003 and mid-2005, ketamine-related drug busts made news in the United States, Canada, India, Australia, the Philippines, and China. Here are some highlights.

  • According to a 2003 Microgram Bulletin article, a mechanic in Maryland discovered what looked like individually wrapped sugar cubes while inspecting a vehicle. Foil-wrapped sugar cubes often contain LSD, but these were laced with ketamine.
  • From the summer of 2003 through the winter of 2005, a huge online pharmacy based in India sold about $20 million worth of unprescribed drugs worldwide. The illegal drug network distributed numerous prescription drugs and one club drug--ketamine--through more than 200 Web sites. Philadelphia Inquirer staff writer Thomas Ginsberg reported that the drugs were shipped from India, Germany, and Hungary to Philadelphia, Pennsylvania, for repackaging. DEA officials nicknamed the international drug investigation "Operation Cyber Chase." The illegal Internet pharmacy bust led to the arrest of twenty-two people in the United States, Canada, and India.
  • In April of 2005, the Central Narcotics Bureau (CNB) of Singapore reported the arrests of a twenty-four-year-old Chinese man and his two associates. The men were selling ketamine and ecstasy. More than 7 grams (0.245 ounces) of ketamine and 75 ecstasy tablets were seized from the trio. According to the CNB web site, the three men faced "a minimum sentence of five years imprisonment and five strokes of the cane" if convicted.
  • In May of 2005, a Special Operations Task Force was tracking Chinese drug manufacturers operating in the Philippines. Johnson Chua, the leader of the illicit drug ring, allegedly concocted and sold a dangerous combination of ketamine and "shabu" (the Asian name for ecstasy). As of that time, drug agents in the Philippines had seized about 7 kilograms (246.92 ounces) of ketamine from Chua's labs, but Chua had not yet been found. Alfred Dalizon, writing in the People's Journal, referred to ketamine as "a new drug craze." According to the Philippines National Police, mixtures of ketamine and ecstasy "could be deadly to users as it could lead even to suicide."

Source Citation

Source Citation   

Gale Document Number: GALE|CV2646400029