Drugs of Abuse: Their Actions & Potential Hazards
 Author:   Samuel Irwin, Ph.D.
Publisher:   Do It Now Foundation

 Publication Date:

  September 2003

 Catalog No:


Chapter 5: Street Drugs

Stimulants & Cocaine

Examples: Methamphetamine (Desoxyn®), amphetamine (Dexedrine®, Benzedrine®), phentermine (Ionamin®), phenmetrazine HCL (Preludin®), methylphenidate (Ritalin®), cocaine, caffeine (in coffee, tea, and soft drinks), ephedrine, phenylpropanolamine or PPA (found in nonprescription diet products).

Demographics: Stimulant use has risen sharply since the mid-1970s, starting with widespread use of nonprescription "lookalike" tablets and capsules and continuing with a nationwide resurgence of amphetamine use in the 1990s. While laws now restrict sales of lookalike drugs, over-the-counter stimulants are still widely used.

Methamphetamine ("crystal") has staged a huge comeback in recent years, but cocaine still ranks as the most commonly-used stimulant in America. According to the National Institute on Drug Abuse, 22.1 million Americans have tried cocaine, and 8.7 percent of the high-school class of 2002 say they've used it at least once.

Smokable cocaine -- freebase, "crack," or "rock" -- fueled the explosion in cocaine use, and these forms of the drug are now generally considered to be among the most dependence-producing drugs known.

Actions: Cocaine, amphetamine, and amphetamine-like drugs are CNS stimulants which elevate basic body processes -- speeding up breathing and heart rate and raising blood pressure. Low doses produce increased alertness and talkativeness, feelings of power and energy, and decrease appetite and desire for sleep. Larger doses cause impaired judgment, insomnia, irritability, anxiety, and transient psychotic episodes and paranoia.

Since stimulant use is so reinforcing--and the drugs themselves so dangerous -- continued use poses serious hazards to users, including:

Behavior: Regular or heavy users may become suspicious, hostile, and paranoid. High doses may trigger full-blown psychotic episodes, characterized by aggression and violence, hallucinations, and delusions.

Overdose: Coma and death can occur from cardiac arrest following high doses of amphetamine and methamphetamine. Cocaine overdose can occur at lower dosage levels, triggering sudden heart attack in otherwise-healthy users.

Depression: Stimulant withdrawal involves deep depression and strong cravings for the drugs. Suicide rates are high among dependent individuals.

Dependence: All stimulants carry high psychological dependence potential. Tolerance develops quickly to the drugs.

Medical Uses: To reduce appetite and overcome chronic fatigue, although on a much reduced scale from 20 years ago. Hyperactive children and adults with attention-deficit disorder may be prescribed Ritalin or Dexedrine to improve concentration. Cocaine was once widely used in dental surgery, while caffeine and PPA are ingredients in many nonprescription diet aids, "stay-awake" pills, and cold and allergy medications.

Main Dangers: Long-term amphetamine use can permanently damage teeth, bones, lungs, liver, and kidneys, and deplete body stores of vitamins and minerals. Heavy cocaine use carries risk of overdose and dependence. Cocaine sniffing can damage nasal tissue and weaken the heart muscle, while freebase use is linked with chronic lung irritation.

Many users turn to CNS depressants to counter the hyperstimulation of constant amphetamine use. Stimulant-depressant combination use can result in multiple addiction.

Withdrawal Symptoms: Severe depression, anxiety, and exhaustion. Intense psychological craving for the drugs can persist for months following cessation of use.

Symptoms of Use: Dilated pupils, loss of appetite, compulsive behavior, belligerence, suspicion, confusion, insomnia.


Examples: Marijuana (Cannabis sativa, Cannabis indica), hashish, hashish oil.

The principle psychoactive ingredient is -9 tetrahydrocannabinol (THC), which varies in concentration in different strains of the plant. Average potency of street marijuana in 1997 was 3.61 percent (up from 2.38 percent in the early 1970s) and 7.57 percent for high-powered strains (sinsemilla).

Actions: Marijuana raises heart rate and lowers blood pressure, and causes reddening of the eyes. Low to moderate dose effects last from two to three hours and can range from euphoria and hilarity to mild lethargy, perceptual changes, and feelings of heightened sensitivity. High dose effects can simulate the perceptual and cognitive changes associated with more potent hallucinogens.

Since the drug's effects on performance -- particularly on tracking ability and reaction speed--can last hours after intoxicating effects fade, pot use can pose significant safety risks. In addition, marijuana may cause problems in learning and social development for adolescent users.

Health problems tied to smoking marijuana include:

Lungs: Marijuana irritates lung tissues. One study found that it delivers three times the tar and five times the carbon monoxide of a tobacco cigarette, raising the risk of lung damage in long-term users.

Immune System: Studies suggest the drug may lower the body's natural defenses against disease.

Nervous System: THC and other ingredients disrupt the production and flow of neurotransmitters in the brain and central nervous system. Researchers suspect these changes may contribute to impaired memory and concentration and reduced motivation in chronic smokers.

Hormonal Effects: Marijuana reduces normal levels of hormones which regulate growth and sexual development. Such irregularities may change growth patterns in adolescents or affect fertility.

Pregnancy Effects: Studies tie maternal use of marijuana to higher levels of miscarriage, stillbirths, and low birth-weight babies, as well as problems in nervous system development.

Marijuana can cause psychological dependence and some tolerance. While it does not appear to produce serious physical dependence, a withdrawal syndrome -- which can include irritability, depression, and insomnia -- is reported following abrupt cessation of use.

Medical Uses: Marijuana has a long history of use as a medicinal agent. Today, research on the drug's possible therapeutic value focuses on its use in treating glaucoma, reducing muscle spasms and seizures, relieving the nausea and vomiting caused by cancer chemotherapy, and reducing the "wasting syndrome" associated with AIDS.

Main Dangers: High dose or chronic use can trigger panic and anxiety episodes in some users. Regular use interferes with learning and concentration and contributes to low motivation and psychological dependence on the drug.

Withdrawal Symptoms: A slight withdrawal syndrome can follow long-term or heavy use (e.g. irritability, sleep disturbances, decreased appetite), but symptoms are mostly transient and disappear within a few weeks.

Symptoms of Use: Intoxication, euphoria, impairment of judgment and coordination, memory lapses, reduced attention span, and fatigue. Possession of marijuana paraphernalia (pipes, rolling papers, etc.). Reddening of the eyes.


Examples: Naturally-occurring: mescaline (peyote), psilocybin (mushroom), nutmeg, jimson weed. Synthetic: Lysergic acid diethylamide (LSD), dimethyltryptamine (DMT), methylenedioxyamphetamine (MDA, MDMA, "ecstasy"), and related compounds.

Actions: The hallucinogens act on the central nervous system by altering the production and processing of chemical neurotransmitters in the brain. Effects can last anywhere from four to 12 hours (MDA, LSD) or as long as 24 hours (TMA, jimson weed).

Hallucinogens trigger profound perceptual and thought changes, which vary according to the individual, situation, and drug used. Other effects can include intense and unpredictable emotions, a sense of detachment from self, and feelings of great insight. In addition, most users are highly suggestible under the influence of hallucinogens, which can further alter the experience.

Physically, hallucinogens increase blood pressure and body temperature, produce dilation of the pupils, and speed up heart and reflex rate. The compounds are also linked to tremors, weakness, profuse sweating, and dizziness.

Hallucinogens can profoundly impair judgment, coordination, and thought, so that driving or other complex activities can be risky, indeed. The drugs carry a slight potential for psychological dependence, but do not produce physical dependence. Some hallucinogens are derived from amphetamine (MDA, MDMA, TMA) and can cause overdose. Tolerance builds quickly and almost completely within a few days.

Medical Uses: LSD, mescaline, MDA, and MDMA have been tested in treatment of a range of psychological disorders and emotional problems, including alcoholism, autism, depression, and psychosis, although the drugs have no currently-accepted medical use.

Main Dangers: Hazards are mostly psychological, and include:

Panic Attacks: The intensity of emotional reactions can trigger anxiety, depression, and confusion, along with an inability to distinguish between reality and the drug's effects.

Psychotic Reactions: Some users experience long-lasting psychological distress, including full-blown psychotic states.

Flashbacks: Unexpected, short-lived recurrences of drug-like effects days or weeks after use of an hallucinogenic compound. LSD flashbacks are psychological in origin and may involve a conditioned response to situational cues associated with previous panic attacks.

New research indicates that MDA and MDMA may disrupt production of the neurotransmitter serotonin. Other dangers derive from the sheer unpredictability of hallucinogens.

Some types (TMA, jimson weed) produce more intense and long-lasting effects than others. Yet because of the illegality of the drugs and a lack of controls associated with their distribution, users can't even be certain which drug they've consumed, much less factor in such considerations as dosage or quality.

Withdrawal Symptoms: None.

Symptoms of Use: Dilated pupils, emotional swings, nausea, impaired coordination, inability to carry on a conversation.

Phencyclidine (PCP) and Ketamine

Examples: 1-(1-phenylcyclohexyl) piperidine (PCP), also known as "angel dust," "embalming fluid," "tic," "THC," and other pseudonyms. Sold in pill, powder, and liquid form, or sprinkled on marijuana or tobacco cigarettes ("sherms"). Ketamine is commonly known as "K" or "Special K."

Demographics: Although PCP is much less prevalent today than in the 1980s, ketamine has become a fixture of the 1990s urban dance-club scene, due to its more-manageable effects.

Actions: Both PCP and ketamine were developed as surgical anesthetics, and are classified as "deliriants" or "psychedelic anesthetics." Their effects are dose-dependent and can resemble stimulants, depressants, anesthetics, and hallucinogens, depending on the amount consumed. The drugs interact with receptors throughout the brain and central nervous system.

Easily the most unpredictable of all psychoactive drugs, PCP effects vary widely depending on the user and the dose:

Low Dose: At low doses (1-5mg), it produces stimulation, euphoria, numbness, and reduced inhibitions along with flushing, sweating, impaired coordination and judgment, and slurred speech.

Moderate Dose: At higher levels (5-10mg), the drug's primary action is CNS depression, accompanied by an excited, confused intoxication. Body image distortion and reduced sensitivity to pain also occur.

High Dose: With larger doses (over 10mg), PCP causes agitation, increased aggression, paranoia, auditory and visual hallucinations, delusions, and near-complete insensitivity to pain. A sharp drop in blood pressure may occur, with muscular rigidity and convulsions, leading to coma and possible death.

Both drugs cause moderate psychological and physical dependence. The drugs' depressant effects are intensified by alcohol and other depressants. Breakdown products are fat-soluble and are stored -- at full psychoactive potential -- in the fatty tissues of the body, producing increased risks of overdose and physiologically-based flashbacks.

Medical Uses: Veterinary anesthetic (PCP). Human surgical anesthetic (ketamine).

Main Dangers: PCP is often sold as an additive to (or substitute for) more scarce drugs, such as LSD, cocaine, heroin, and mescaline, posing serious risks to users who do not realize they are taking PCP. But whether taken accidentally or intentionally, the drug carries a range of risks:

Accidents: PCP reduces sensitivity to pain, heightens aggression, and powerfully impairs judgment and coordination, producing high risk of injury or death by falls, drowning, etc.

Panic Attacks: "Bad trips" on PCP can involve confusion, mood swings, delusions and hallucinations. The attacks are difficult to treat and can lead to long-term emotional problems.

Psychosis: In some users, PCP can "unmask" underlying emotional and behavioral problems, and trigger psychotic states.

Withdrawal Symptoms: None.

Symptoms of Use: Intoxication, poor coordination, inability to carry on a conversation, bizarre behavior. Sweating, flushing, muscular rigidity, and occasional rhythmic rotation of the eyeballs (nystagmus) may occur. High-dose symptoms resemble schizophrenia.

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This is one in a series of publications on drugs, behavior, and health published by Do It Now Foundation. Check us out online at www.doitnow.org.