A drug is a chemical substance that is used to alter some aspect of the body's Choose...physicalgeneticbiologicalmental processes. Many drugs act by binding to receptors on the surface of cells. Drugs that bind to receptors on cells resemble natural substances called Choose...vitamins and minerals organs and tissues hormones and neurotransmitters chromosomes and genes . Some drugs can kill bacteria by binding to receptors on the bacteria's surface and blocking Choose...genetic information sugar utilization protein synthesis movement. Drugs also may be harmful by causing allergies, birth defects, and undesirable side effects. The effectiveness and safety of a new drug must be tested in a Choose...medical placebo controlled-double blind government sponsored pharmaceutical company study before it is approved for use. More than one fourth of all prescription drugs are Choose...tranquilizersantibiotics psychoactive illegal and affect processes in the brain. Drug companies spend enormous amounts of money advertising their drugs, especially to physicians. Drug companies spend more than Choose...$100 $1,000 $10,000 one million dollars per year per physician to encourage doctors to prescribe their drugs. Drug companies even advertise prescription drugs to consumers on TV and in the media. Use of any drug to the point where health or functioning is adversely affected is called Choose...stimulationillegal use recreationaldrug abuse . Drugs such as cocaine and amphetamines are Choose...analgesics stimulants appetite suppressants depressants and increase activity of the nervous system. Drugs used medically to treat severe pain are called Choose...sedatives depressantsopiates hallucinogens. These drugs are generally addictive which means that increasingly larger doses of the drug is needed to produce the same relief. Because of their ability to alter mental states, many plant-derived drugs are classified as Choose...sedatives depressantsopiates hallucinogens.