alkaloid: the active element of a drug in its natural state.

allergy: extreme reaction to drug element.

amotivational syndrome: disinterested, uninvolved, unmotivated, passive, lethargic as associated with cannabis abuse.

analgesic: numbs pain while user is alert.

anesthesia: loss of sensitivity, usually in unconscious state.

antagonist: blocks effects of another drug.

antitussive: prevents coughing.

cardiac arrest: stopping of all heart function.

cardiovascular system: heart and blood vessels.

central nervous system (CNS): brain and spinal cord.

cerebellum: brain center controlling muscle coordination.

cerebral cortex: gray matter on upper surface of brain controlling sensory perception, thought process, control of movement.

chronic: long lasting.

cirrhosis: progressive liver disease, often related to alcohol abuse.

coma: unconsciousness beyond arousal.

congener: chemically related to another drug,

convulsion: severe, involuntary muscle spasm, usually with loss of consciousness.

cross-dependence: a similar drug can prevent withdrawal effects, but will not necessarily prolong other effects.

cross-tolerance: insensitivity to similar effects of other drugs.

dependence: craving or physical need for a drug which interferes with physical and mental health, social responsibility and well-being.

depressant: slows functions of specific organ system.

depression: physical slowing of functions or emotional despair and unhappiness.

derivative: extracted from another drug by chemical process.

detoxification (detox): eliminating harmful drug effects.

disinhibitor: causing loss of inhibitions.

dissociative: feelings of separation or distance from situation.

drug: any natural or manufactured substance with physiological or psychological effects.

DTs: delirium tremens related to alcohol withdrawal.

euphoria: heightened feeling of happiness, well-being.

hallucination: an unreal perception believed to be real.

hemorrhage: loss of blood from blood vessels.

hepatitis: inflammation of the liver related to toxic substances or viral infection.

hypertension: extremely high blood pressure.

hyperthermia: extremely high body temperature.

hypotension: extremely low blood pressure.

hypothermia: extremely low body temperature.

hypnotic: sleep inducing drug.

intoxication: both inebriation and poisoning.

intramuscular: within a muscle.

intravenous: within a vein

metabolism: body conversion of substances into various other substances.

narcotic: a drug which has a numbing or deadening effect.

nasal rebound effect: after frequent use of decongestant spray, nose clogs from effects and tolerance develops.

needle pleasure syndrome: experienced addicts associate pleasure with any drug or non drug injection.

opiate: natural or semisynthetic narcotic analgesic derived from the opium poppy.

opioid: a synthetic narcotic analgesic, also used in the general sense for all narcotic analgesics.

OTC: over-the-counter drug widely available without prescription.

overdose: amounts over the prescribed or indicated doses that produce damaging effects.

paranoia: extreme suspicion.

parkinsonism: brain disorder affecting involuntary twitches, tremors, unusual walk, Parkinson's disease.

pseudohallucination: perceived as real but known to be unreal by drug user.

psychoactive: affecting emotions, thoughts, behavior.

psychosis: severe mental disorder.

respiratory arrest: stopped breathing.

Reye syndrome: uncommon but sometimes fatal disease associated with the use of aspirin by children under age 16 who have chicken pox or a viral syndrome, causing violent headaches, vomiting, sleepiness, irritability, disorientation and delirium.

schizophrenia: bizarre behavior with extreme disturbances in thought and mood.

sedation: state of extreme calm and relaxation produced by a drug.

seizure: convulsions or other physical or psychic evidence of abnormal electric activity in the brain.

side effect: effect, usually undesirable, which accompanies primary desired effect.

solvent: liquid used to dissolve other substances .

subcutaneous: under the skin.

tolerance: body adaptation to repeated drug effects requiring increased dosage for original experiences.

toxic psychosis: severe mental disorder caused by psychoactive substances.

ulcer: injury to skin or mucous surface in body.

withdrawal sickness: physical and psychological effects when use of drug is stopped.