Hanson 10e Pp Ts Ch06


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Hanson 10e Pp Ts Ch06

  1. 1. CNS Depressants: Sedative-Hypnotics Chapter 6
  2. 2. Introduction to CNS Depressants <ul><li>Why are CNS depressants problematic? </li></ul><ul><ul><li>Usually prescribed under physician direction </li></ul></ul><ul><ul><li>Can cause very alarming and dangerous behavior if not closely monitored </li></ul></ul><ul><ul><ul><li>Most problems associated with these drugs due to inadequate professional supervision </li></ul></ul></ul>
  3. 3. Introduction to CNS Depressants (continued) <ul><li>Why are CNS depressants problematic? </li></ul><ul><ul><li>Seemingly unrelated drug groups can cause CNS depression </li></ul></ul><ul><ul><li>Combination use can cause dangerous drug interactions </li></ul></ul><ul><ul><li>Can cause disruptive personality changes </li></ul></ul>
  4. 4. The History of CNS Depressants <ul><li>Attempts to find CNS depressants other than alcohol began in the 1800s. </li></ul><ul><li>Bromides were introduced to treat nervousness and anxiety in the 1800s. </li></ul><ul><ul><li>Very popular but toxic. </li></ul></ul><ul><li>In the early 1900s, bromides were replaced by barbiturates. </li></ul><ul><ul><li>Initially heralded as safe and effective. </li></ul></ul><ul><ul><li>Problems with tolerance, dependence, and safety became apparent. </li></ul></ul>
  5. 5. The History of CNS Depressants (continued) <ul><li>In the 1950s the first benzodiazepines were marketed as substitutes for barbiturates. </li></ul><ul><ul><li>Relatively safe when used for short periods </li></ul></ul><ul><ul><li>Long-term use can cause dependence and withdrawal problems </li></ul></ul>
  6. 6. The History of CNS Depressants (continued) <ul><li>Benzodiazepines were routinely prescribed for stress, anxiety, or apprehension. </li></ul><ul><ul><li>In 1973 100 million prescriptions were written for benzodiazepines. </li></ul></ul><ul><ul><li>Twice as many women as men taking them. </li></ul></ul><ul><ul><li>“Mother’s Little Helper” by the Rolling Stones. </li></ul></ul><ul><li>As medical community became aware of the problem, use of depressants declined. </li></ul>
  7. 7. The Effects of CNS Depressants <ul><li>CNS depressants reduce CNS activity and diminish the brain’s level of awareness. </li></ul><ul><li>Depressant drugs include: </li></ul><ul><ul><li>Benzodiazepines </li></ul></ul><ul><ul><li>Barbiturate-like drugs </li></ul></ul><ul><ul><li>Alcohol </li></ul></ul><ul><ul><li>Antihistamines </li></ul></ul><ul><ul><li>Opioid narcotics like heroin </li></ul></ul>
  8. 8. The Effects of CNS Depressants (continued) <ul><li>Depressants are usually classified according to the degree of their medical effects on the body. For example: </li></ul><ul><ul><li>Sedatives cause mild depression and relaxation </li></ul></ul><ul><ul><ul><li>Anxiolytic —drugs that relieve anxiety </li></ul></ul></ul><ul><ul><li>Hypnotics induce drowsiness and encourage sleep </li></ul></ul><ul><ul><ul><li>Amnesiac effects can cause the loss of memory </li></ul></ul></ul>
  9. 9. The Effects of CNS Depressants (continued) <ul><li>The same drug can cause different effects based on dose. </li></ul><ul><ul><li>Low dose (sedatives—relieve anxiety and promote relaxation) </li></ul></ul><ul><ul><li>Higher doses (hypnotics—can cause drowsiness and promote sleep) </li></ul></ul><ul><ul><li>Even higher doses (anesthetics—can cause anesthesia and are used for patient management during surgery) </li></ul></ul>
  10. 10. Types of CNS Depressants <ul><li>Benzodiazepines: Valium-Type Drugs </li></ul><ul><ul><li>Prescribed for anxiety and sleep </li></ul></ul><ul><li>Medical uses </li></ul><ul><ul><li>Relief from anxiety, treatment of neurosis, relaxation of muscles, alleviation of lower-back pain, treatment of convulsive disorders, induction of sleep, relief from withdrawal symptoms, induction of amnesia </li></ul></ul>
  11. 11. Types of CNS Depressants (continued) <ul><li>Mechanisms of action for benzodiazepine </li></ul><ul><ul><li>Affect neurons that have receptors for the neurotransmitter GABA </li></ul></ul><ul><li>GABA—inhibitory transmitter in brain regions </li></ul><ul><ul><li>Limbic system (alter mood) </li></ul></ul><ul><ul><li>RAS (cause drowsiness) </li></ul></ul><ul><ul><li>Motor cortex (relax muscles) </li></ul></ul>
  12. 12. Types of CNS Depressants (continued) <ul><li>Types of benzodiazepines </li></ul><ul><ul><li>Many benzodiazepine compounds available in the U.S. </li></ul></ul><ul><ul><li>Distinguished primarily by their duration of action: short-acting (hypnotics), long-acting (sedatives) </li></ul></ul><ul><li>Side effects </li></ul><ul><ul><li>Drowsiness to paradoxical effects </li></ul></ul><ul><ul><li>Tolerance, dependence, withdrawal, and abuse </li></ul></ul>
  13. 13. Types of CNS Depressants (continued) <ul><li>Barbiturates played an important role as sedative-hypnotic agents. </li></ul><ul><li>However, due to their narrow margin of safety and their abuse liability, they were replaced by benzodiazepines. </li></ul><ul><ul><li>Caused many negative side effects, from nausea to death, from respiratory or cardiovascular depression </li></ul></ul>
  14. 14. Other Types of CNS Depressants <ul><li>Drugs with barbiturate-like properties </li></ul><ul><ul><li>Chloral hydrate </li></ul></ul><ul><ul><li>Glutethimide </li></ul></ul><ul><ul><li>Methyprylon </li></ul></ul><ul><ul><li>Methaqualone </li></ul></ul><ul><li>Antihistamines </li></ul><ul><li>GHB (gamma hydroxybutyrate) </li></ul>
  15. 15. Patterns of Abuse with CNS Depressants <ul><li>The American Psychiatric Association considers dependence on CNS depressants a psychiatric disorder. </li></ul>
  16. 16. Patterns of Abuse with CNS Depressants (continued) <ul><li>People most likely to abuse CNS depressants include individuals who </li></ul><ul><ul><li>Use drugs to relieve continual stress </li></ul></ul><ul><ul><li>Paradoxically feel euphoria and stimulation from depressants </li></ul></ul><ul><ul><li>Use depressants to counteract the unpleasant effects of other drugs of abuse </li></ul></ul><ul><ul><li>Combine depressants with alcohol and heroin to potentiate the effects </li></ul></ul>
  17. 17. Patterns of Abuse with CNS Depressants (continued) <ul><li>Detoxification —the elimination of a toxic substance, such as a drug, and its effects </li></ul><ul><ul><li>With CNS depressants, this is achieved by substituting a longer-acting barbiturate for the offending CNS depressant and gradually reducing the dose. </li></ul></ul>