Depressants and Inhalants

Depressants and Inhalants Depressants a class of drugs that decrease central nervous system (CNS) activing • have a widespread effect in the brain • also called sedatives or hypnotics Sedatives treat anxiety hypnotics treat insomnia History: Before Barbiturates *Chloral hydrate "Started with "mickey finn" adding the substance in drinks first synthesized in 1832 and used clinically in 1870 one to two grams induce sleep in less than an hour repeated use leads to gastric irritation Paraldehyde "Synthesized in 1829 and used clinically in 1882 effective and has a wide safety margin has an extremely noxious taste and an odor that permeates the breath of the user. Barbiturates •first introduced in 1903 "So popular and useful that over 2.500 examples were synthesized popular barbiturates included phenobarbital, amobarbital, and secobarbital "grouped based on their duration of action, which corresponds to their time of onset "Short acting and rapid anset: used to induce sleep and are prescribed in high dases "long acting and delayed onset: used to reduce anxiety and are prescribed in low doses Concerns About Barbiturates Overdose deaths intentional and accidentat Caused by respiratory depression alouse and dependence reinforcing effects of a drug are related to the rapidity of onset of effects Short acting drugs are more likely to lead to psychological dependence Concerns led to search for safer medications Meprobamate * widely prescribed after approval in 1995 Can produce psychological and physical dependence like barbiturades Still available as a prescription drug - largely replaced by benzodiazepines Methaqualone Other names brands such as Quaalude and Sopor "Slang includes ludes" or "Sopors" despite problems in other countries, the drug was introduced in the U.S. in 1965 package insert read "addiction potential not established" physicians overprescribed, thinking the drug was a safe alternative to barbiturates widely misused and abused Scheduling history put on senedule 2 in 1973 put on Schedule I in 1985 Benzodiazepines •first introduced in 1960 Chlordiazepoxide, or librium, the first commercially marketed benzodiazepine * reduces anxiety and produces less drowsiness than barbiturates much larger safety margin before overdose death occurred in animals *physical dependence was rare overdose occurred only when combined with omer depressants or alconal 1972 to 1978 diazepam, or valium, became the best seller among all prescription drugs. however, dependence and overdose can occur dose level and time course are critical factors "overdose deaths are more likely when a drug is sold in higher doses psychological dependance develops most rapidly when the drug hits the brain quickly physical dependence occurs when the drug leaves the system more rapidly than the body can adapt are benzoakazepines safer than barbiturates? more differences might exist among the barbiturates and among the benzodiazepines fewer differences might exist between these two classes of drugs Benzodiazepines: Rohypnol *a 1990s version of "mickey finn" * produces profound intoxication when mixed with alkohol reportedly used as a "date-rape' drug "Supped into drinks of women in 1997, a change in the formulation caused it to produce a distinctive color when dissolved in a drink rohypnol effects are not much different from the effects of other CNS depressants Nonbenzodiazepine Hypnotics informally referred to as the "Z-drugs" Similar to benzodiazepines but have a different Chemical Structore Zolpidem, or ambien, became the most widely prescribed hypnotic Short duration of action rapid onset initially thought to be safer than benzodiazepines withdrawal Symptoms have been reported •listed in Schedule Iv Mechanism of Action: Sedatives and Hypnotic benzodiazepines bind to their receptor site and enhance the inhibitory effects of GABA on its receptors, and barbiturates act as a separate binding site nearby GABA receptor complex includes the barbiturates binding site and the benzodiazepine receptor nonbenzodiazepine hypnotics - entirely new class of drugs that may selectively bind to different sites on the GABA receptor complex