Drugs, Deviance, & Social Control Exam 2 Chapter 6 (CNS Depressants: Sedative-Hypnotics) Study Guide
CNS depressant drug action, effect - important distinguishing characteristic: Anesthetic effect
-Anesthesia: A state characterized by loss of sensation or consciousness -Used to achieve a controlled state of unconsciousness so that a patient can be treated, usually by surgery, in relative comfort and without memory of a traumatic experience -With the exception of benzodiazepines, if the dose of most of the depressants is increased much more, coma or death will ensue because CNS becomes so depressed that vital centers controlling breathing and heart activity cease to function properly
CNS depressant drug action, effect - important distinguishing characteristic: Hypnotic effect
-Hypnotics = induce drowsiness and and encouraged sleep -Up to 70 million Americans have issues with sleeping so drugs like the benzodiazepines are used to help -Used to encourage sleep by inducing drowsiness -Often when depressants are used as hypnotics they produce amnesiac effects -Amnesiac: Causing the loss of memory
CNS depressant drug action, effect - important distinguishing characteristic: Sedative effect
-Sedatives = mild depression and relaxation -Related to anxiety -Sedatives: CNS Depressants used to relieve anxiety, fear, and apprehension -Causes mild depression of the CNS and relaxation -This drug effect is often used to treat extreme anxiety and often is referred to as anxiolytic -Anxiolytic: Drug that relieves anxiety
Other Types of CNS Depressants
Drugs with barbiturate-like properties: -Chloral Hydrate - "Noctec" -Glutethimide - "Doriden" -Methaqualone - "Quaalude" -Generally used to treat insomnia Antihistamines: -Used in both prescription and nonprescription medicinal products -Relieve symptoms of colds, allergies, motion sickness -Newer antihistamines -> decreased central effect Propofol: -"Diprivan" Gamma Hydroxybutyrate (GHB): "Xyrem": -Used for general anesthetic, insomnia, depression, and narcolepsy
Benzodiazepine's: Medical utility // Margin of safety // Contemporary trends in use // Side effects // Concerns with prolonged use/abuse // Methods for treatment
Benzodiazepines: Valium-Type Drugs: -Wider margin of safety, preferred prescribed CNS depressants -First marketed around 1960 -Top selling prescription from 1972-78 -Treats anxiety, neurosis, back pain, convulsive disorders, insomnia, relief from withdrawal symptoms associated with narcotic and alcohol dependence, and induction of amnesia; usually for preoperative administration just before or during the surgery or for very uncomfortable medical procedures -Same effects on CNS as barbiturates: *Engages GABA *Range of effect length Side Effects: -Drowsiness, increased restlessness -Impaired respiration at high doses -Few verified instances of death -Tolerance, dependence, withdrawal, and abuse -Typically the preferred prescribed CNS depressants for anxiety and sleep -Because of their wide margin of safety (death from overdose is rare) -benzodiazepines have replaced barbiturate-like drugs for use as sedatives and hypnotics -Originally referred to as Minor Tranquilizers, but terminology erroneously implied that they had pharmacological properties similar to those of antipsychotic drugs (Major Tranquilizers), when they are actually very different -First true benzodiazepine = Chlordiazepoxide (Librium) *Developed for medical use and marketed about 1960 -Valium came out around the same time, and was so widely received that from 1972-1978 it was the top-selling prescription drug in the U.S -Valium's popularity has since declined and has been replaced by benzodiazepines such as alprazolam (Xanax) and lorazepam (Ativan) -Because of drug dependence problems, benzodiazepines are now classified as Schedule IV Drugs -Clinicians are worried about the overprescribing of these and warn about dependence issues -Benzodiazepines are distinguished primarily by their duration of action -Short-acting drugs are used as hypnotics to treat insomnia, thus allowing the user to awake in the morning with few aftereffects -Long-lasting benzodiazepines tend to be prescribed as sedative, giving prolonged relaxation and relief from persistent anxiety -One reason for the long action is some benzodiazepines is that they are converted by the liver into metabolites that are as active as the original drug *Ex: Valium has been reported to have an approximate half-life of more than 100 hours and is converted by the liver into several active metabolites, including oxazepam (which itself is marketed as a therapeutic benzodiazepine) Mechanisms of Action: -Unlike barbiturates which cause general depression of most neural activity, benzodiazepines selectively affect those neurons that have receptors for the Neurotransmitter Gammaaminobutyric Acid (GABA) -GABA is a very important inhibitory transmitter in several regions of the brain: the limbic system, the reticular activating system, and the motor cortex -In the presence of benzodiazepines, the inhibitory effects of the GABA are increased -Depression of activities in these brain regions likely accounts for the ability of benzodiazepines to alter mood (a limbic function), cause drowsiness (a reticular activating system function), and relax muscles (a cortical function) Side Effects: -Drowsiness, light headaches, lethargy, impairment of mental and physical activities, skin rashes, nauseas, diminished libido, irregularities in the menstrual cycle, blood cell abnormalities, and increased sensitivity to alcohol and other CNS depressants -There are very little cases of benzodiazepine overdoses alone, but a lot when mixed with other substances -Benzodiazepines have less effects on REM sleep than barbiturates -Consequently, sleep under the influence of them is more likely to be restful and satisfying -However, prolonged use of them may cause rebound increases in REM sleep and insomnia when the drug is stopped, especially if used for long periods of time -REM Sleep: The restive phase of sleep associated with dreaming -Other rare occasions, benzodiazepines can have paradoxical effects (unexpected effects), producing unusual responses such as nightmares, anxiety, irritability, sweating, and restlessness -Bizarre, uninhibited behavior-- extreme agitation with hostility, paranoia, and rage-- may occur -The FDA almost shut down Halcion due to complains to "amnesia, confusion, paranoia, hostility, and seizures", however they later concluded that the benefits outweigh the risks Tolerance, Dependence, Withdrawal, and Abuse: -Although the ED/LD ratio is low, should prescribe carefully due to the high rate of abuse -Withdrawal can mimic the condition for which the benzodiazepine was prescribed *Ex: withdrawal symptoms can include anxiety, or insomnia *In such cases, the clinician can be fooled into thinking that the underlying emotional disorder is still present and may resume drug therapy without realizing that the patient has become drug dependent -Longer use withdrawal symptoms can include depression, panic, paranoia, and convulsions Duration of Abstinence & Symptoms: -1-3 Days: Often no noticeable symptoms -3-4 Days: Restlessness, agitation, headaches, problems with eating, and inability to sleep -4-6 Days: Th preceding symptoms plus twitching of facial and arm muscles and feeling of intense burning in the skin -6-7 Days: The preceding symptoms plus seizures
CNS Depressants
CNS Depressants: Sedative-Hypnotics: -Depressants, Narcotics, and Stimulus are the three main things* -Majority of people who abuse these are getting them from a pharmaceutical source The Appeal of CNS Depressants: -CNS Depressants = Sedatives, Tranquilizers -Slow Brain Activity + Slows the CNS = Slows the body's functioning -Properties make them useful for treating anxiety and sleep disorders; appealing to people with emotional problems Major types of depressant drugs: -Barbiturates -Benzodiazepines -Alcohol History of CNS Depressants: -Before the era of modern medicine, people turned to alcohol to ease tension -Alcohol = most commonly abused drug (historically and today) -The search for other options began in the 1800s -Surge of temperance during that time period -Bromide compounds (potassium bromide) frequently used sedatives *Use in OTC sedatives, headache remedies *FDA ban in 1975 *Currently used in veterinary medicine -Barbiturates replaced bromides as sedative of choice in the early 1900s *"Safe and Effective" *Reality = narrow margin of safety *More severe depression as it builds up *Effects both mental and physiological functioning -Benzodiazepines marketed as substitutes in the 1950s *Relatively safe (short term use) *Millions of prescriptions -During the 1970s and 1980s there was an epidemic of prescriptions written for CNS depressants -Approximately twice as many women as men were taking these drugs at this time; a similar gender pattern continues today General Effects of CNS Depressants: -Classified according to the degree of their medical effects on the body -Sedatives = mild depression and relaxation *Related to anxiety -Hypnotics = induce drowsiness and and encouraged sleep -Dosing is key! -The same drug can cause different effects depending on the dosage -Sedative -> Hypnotic -> Anesthetic -Often used in a persistent fashion = tolerance -When tolerance develops, what is the general response? *You have to up the dose *Eventually they can get to a high enough dose where it can be sustained -Problem with giving higher doses is that people can divert their drugs to other people Major Types of CNS Depressants - Drug Effects: -Not all CNS depressants are created equal -Carrying margins of safety -Differing potential for abuse Problems with CNS Depressants: 1.) CNS Depressants are usually not obtained illicitly and self-administered but rather are prescribed under the direction of a physician 2.) Use of them can cause very alarming-- even dangerous-- behavior if not monitored closely; most problems associated with these drugs occur due to inadequate professional supervision and chronic use 3.) Several seemingly unrelated drug groups have some ability to cause CNS depression and all too frequently are the cause of death by drug overdoses. When these drugs are combined, bizarre and dangerous interactions can result. Particularly problematic is the combination of alcohol with another CNS depressant 4.) CNS Depressants can cause disruptive personality changes that are unpredictable and sometimes very threatening -Antihistamines: Drugs that often cause CNS depression, are used to treat allergies, and are often included in OTC sleep aids -Depressants are usually classified according to the degree of their medical effects on the body -The effects of CNS depressants tend to be dose dependent -Thus, if you were to take a larger dose of a sedative it might have a hypnotic effect -Often the only difference between a sedative and a hypnotic effect is the dosage; consequently, the same drug may be used for both purposes by varying the dose -By increasing the dose still further, an anesthetic state can be reached
