Drogas

Depressants
Historically, people of almost every culture have used chemical agents to induce sleep, relieve stress, and allay anxiety. While alcohol is one of the oldest and most universal agentsused for these purposes, hundreds of substances have been developed that produce central nervous system depression. These drugs have been referred to as downers, sedatives, hypnotics, minortranquilizers, anxiolytics, and anti-anxiety medications. Unlike most other classes of drugs of abuse, depressants are rarely produced in clandestine laboratories. Generally, legitimate pharmaceutical products arediverted to the illicit market. A notable exception to this is a relatively recent drug of abuse, gamma hydroxybutyric acid (GHB).
Choral hydrate and paraldehyde are two of the oldest pharmaceuticaldepressants still in use today. Other depressants, including gluthethimide, methaqualone, and meprobamate have been important players in the milieu of depressant use and abuse. However, two majorgroups of depressants have dominated the licit and illicit market for nearly a century, first barbiturates and now benzodiazepines.
Barbiturates were very popular in the first half of the 20th century.In moderate amounts, these drugs produce a state of intoxication that is remarkably similar to alcohol intoxication. Symptoms include slurred speech, loss of motor coordination, and impaired judgment.Depending on the dose, frequency, and duration of use, one can rapidly develop tolerance, physical dependence, and psychological dependence to barbiturates. With the development of tolerance, themargin of safety between the effective dose and the lethal dose becomes very narrow. That is, in order to obtain the same level of intoxication, the tolerant abuser may raise his or her dose to a levelthat may result in coma or death. Although many individuals have taken barbiturates therapeutically without harm, concern about the addiction potential of barbiturates and the ever-increasing number...