WHAT IT IS

Names: Heroin, dust, "H." horse, junk, smack, scag, Mexican mud, China white, black tar.

Type: Semisynthetic narcotic pain killer, opiate.

Forms: Fine, white crystalline powder, water soluble and bitter tasting.

Combinations: With amphetamines, "bombitas" with cocaine, "dynamite," "speedball," "whizbang" with marijuana, "atom bomb," "A-bomb."

Usage: Injected (water solution) into bloodstream, "mainlining." Under skin,"skin popping," or into muscle. Sniffing (powder), "snorting." Smoking (vapor), "chasing the dragon." Swallowing (powder wrapped in tissue or bread).

Legal Status: Illegal in U.S. for all use. Legal in some countries for extreme cancer or other pain and for regulated maintenance of addicted users.

WHAT IT FEELS LIKE

An immediate, powerful orgasmic rush, followed by peacefulness, lack of pain, euphoria, leading to drowsiness ( a "nod"), inactivity, inability to concentrate, small pupils, droopy eyelids, limited vision, slowed breathing, nausea and vomiting, lack of appetite, constipation, reduced sex drive, increased urination, itching or burning on skin, low body temperature, sweating.

WHAT IT DOES

To Your Mind: Metabolizes into morphine and depresses central nervous system, suppressing pain sensation and relieving anxiety.

To Your Body: Affects both gastrointestinal and respiratory systems, causing constipation and slow breathing.

Special Characteristics: Repeated use develops tolerance to nausea and vomiting. Then, tolerance to desired effects also develops, requiring increased dosage.

HOW IT CAN HURT YOU

Drowsiness may progress to coma. Irregular breathing and heartbeat, respiratory and cardiac arrest. Slowed breathing may lead to oxygen starvation and brain damage. Needle infection may cause collapsed veins, tetanus, hepatitis, endocarditis or Acquired Immune Deficiency Syndrome (AIDS).

Death results from overdose which brings on lung and heart complications. Overdose can result from purchase of impure and/or unpredictable street drugs.

Dependence develops even when ''chipping,'' using heroin infrequently and in low doses. The tolerance which develops causes progression to higher doses. Fear of withdrawal creates dependence in itself. Withdrawal and abstinence reduce tolerance for only a brief period.

Psychological dependence can be prolonged after withdrawal with depression, anxiety, inability to sleep, lack of appetite, restlessness and craving for the drug.

WHEN TO GET HELP

• Do you think about how and when you are going to use heroin again?
• Is your work or school performance affected by your drug use?
• Are you having problems with family and friends?
• Do you spend more on heroin than you can afford?
• Do you use drugs in addition to heroin?

One "yes" and your common sense is all it takes to know it's time to get smart about heroin and the rest of your life.

Fact: Of all similar drugs, you are most likely to become addicted to heroin.