Concept Practice
How Do Therapeutic Drugs Work?

Chapter 38. How Do Therapeutic Drugs Work?

agonist
a chemical or drug that increases the effect of a neurotransmitter
antagonist
a chemical or drug that decreases the effect of a neurotransmitter
antianxiety drugs
drugs that calm a person and reduce stress and tension
antidepressant drugs
drugs that boost mood by increasing the availability of neurotransmitters serotonin or norepinephrine
antipsychotic drugs
drugs that reduce schizophrenic symptoms by blocking the effect of the neurotransmitter dopamine
bipolar disorder
a psychological disorder characterized by dramatic mood swings from mania to deep depression
depression
extreme mood swing in a negative direction, accompanied by feelings of worthlessness, helplessness, and hopelessness
dopamine
neurotransmitter involved in movement and motivation
GABA
most common inhibitory neurotransmitter in the brain; typically decreases brain activity and behavior
glutamate
most common excitatory neurotransmitter in the brain; typically increases brain activity and behavior
mania
a symptom of bipolar disorder; characterized by a dramatically elevated mood
mood-stabilizing drugs
drugs that reduce the dramatic mood swings of bipolar disorder
neuron
a single nerve cell, forming the basic unit of the nervous system
neurotransmitters
chemical messengers released by the axon terminal into the synaptic gap between neurons
norepinephrine
neurotransmitter involved in arousal and mood
psychological disorder
a disturbance in a person’s thinking, behavior, or emotions serious enough to cause distress
schizophrenia
a psychological disorder characterized by disturbed, irrational thinking and inappropriate emotional behavior
serotonin
neurotransmitter involved in mood and sleep
therapeutic drugs
drugs that are used in the treatment of psychological disorders
How Do Therapeutic Drugs Work?
true
true
true
Various pills and tablets
Science Photo Library/Getty Images
Learning Objective:

Identify the basic principles of drug action.

concept_review

Review

Select the NEXT button and continue with the Review.

1. Therapeutic drugs are used to treat psychological disorders. These drugs fall into four main categories: antianxiety drugs, antidepressant drugs, antipsychotic drugs, and mood-stabilizing drugs.

concept_review

Review

Select the NEXT button and continue with the Review.

young man bites his nails
file404/Shutterstock
Antianxiety drugs work as agonists by increasing the effects of GABA.

2. Standard antianxiety drugs calm a person by slowing neural activity. These drugs enhance the action of GABA, the most common inhibitory neurotransmitter in the brain. Most tranquilizing drugs, including Xanax, are GABA agonists.

concept_review

Review

Select the NEXT button and continue with the Review.

ttractive young woman ( Acting ) as someone in pain or sad.
Paul Matthew Photography/Shutterstock
Antidepressant drugs work as agonists by increasing the effects of serotonin and norepinephrine.

3. Antidepressant drugs try to elevate a depressed person's mood. Depressed individuals typically have unusually low levels of the neurotransmitters norepinephrine (which influences arousal) and serotonin (which regulates mood). Most mood-boosting drugs, including Prozac, are agonists to serotonin or norepinephrine, or both.

concept_review

Review

Select the NEXT button and continue with the Review.

Voice within us
iStock/Getty Images
Antipsychotic drugs work as antagonists by decreasing the effects of dopamine.

4. Antipsychotic drugs try to reduce the major symptoms of schizophrenia, such as distortions in perception and thinking. Individuals with schizophrenia typically have high levels of the neurotransmitter dopamine. Most antipsychotic medications, such as Haldol or Nardil, are antagonists to dopamine.

concept_review

Review

Select the NEXT button and continue with the Review.

Screen 6: Mood stabilizing drugs work as agonists by increasing the effects of GABA. They also work as antagonists by decreasing the effects of glutamate.

5. Mood-stabilizing drugs are used in the treatment of bipolar disorder. Lithium, the most commonly used of these stabilizers, appears to be a GABA agonist but an antagonist to glutamate, the most common excitatory neurotransmitter. Lithium works especially well in reducing episodes of mania.

video
true

Practice 1: Activating and Blocking Receptors

Play the animation to watch the effect of the stimulant drug nicotine and the antipsychotic drug Haldol on neurotransmitter function.

conceptpractice_drugaction_01
Current Time 0:00
Duration 0:00
Loaded: 0%
Stream Type LIVE
Remaining Time 0:00
 
1x
    • Chapters
    • descriptions off, selected
      video
      true

      Practice 2: Blocking Reuptake of Neurotransmitter

      Play the animation to watch Prozac’s effect in blocking reuptake of serotonin.

      conceptpractice_drugaction_02
      Current Time 0:00
      Duration 0:00
      Loaded: 0%
      Stream Type LIVE
      Remaining Time 0:00
       
      1x
        • Chapters
        • descriptions off, selected
          video
          true

          Practice 3: Slowing the Removal of Neurotransmitter

          Play the animation to watch Nardil’s effect in blocking the enzyme breakdown process.

          conceptpractice_drugaction_03
          Current Time 0:00
          Duration 0:00
          Loaded: 0%
          Stream Type LIVE
          Remaining Time 0:00
           
          1x
            • Chapters
            • descriptions off, selected
              radio_quiz_upd
              0,1,1,0,1,0,0,1
              Select the NEXT button and move to the Quiz 2.
              Try to respond to the statements again.

              Quiz 1

              For each statement, select one of the buttons to indicate whether the statement is True or False. When all of the buttons have been chosen, select the CHECK ANSWER button.

              TrueFalse

              Many depressed individuals have excessively high levels of the neurotransmitter serotonin, which helps to regulate mood.

              Individuals who are exhibiting the bizarre symptoms of schizophrenia usually improve when given a drug that acts as dopamine antagonist.

              Some antidepressant drugs slow the removal of serotonin from the synaptic gap, This extends the time that serotonin molecules are available to stimulate the receptors of the next neuron, significantly increasing their mood-boosting effect.

              Some drugs block the natural process that breaks down a neurotransmitter into its simpler parts. These drugs would be antagonists to the neurotransmitter.
              quiz2

              Quiz 2

              Select each PLAY button to watch an animation of one aspect of the synaptic transmission with or without the influence of a drug. Then drag the labels to identify the type of process shown in each animation. When all the labels have been placed, select the CHECK ANSWER button.

              This page contains a matching activity. You need to match a label with a definition. Choose the label using TAB button. Then enter one of the following numbers to select the corresponding answer. You can change the location of the label only while this label is selected. There are 3 videos on the screen that display different sequencing of events. The first video demonstrates how neurotransmitters unbind from receptors on the dendrite of the second cell and are reuptaken into the axon terminal of the first cell. The second video demonstrates how neurotransmitters are released from the axon terminal of the first cell and bind to receptors on the dendrite of the second cell. The third video demonstrates how neurotransmitters unbind from the receptors on the dendrite of the second cell but are blocked from being reuptaken back into the first cell's axon terminal.
              Select the NEXT button and move to Conclusion.
              Perhaps you should go back to review how therapeutic drugs work.
              Neurotransmitters being released and binding to receptors
              Neurotransmitters unbinding from receptors followed by reuptake into terminal
              Neurotransmitters unbinding from receptors, but reuptake is blocked
              asset/activities/drug_action/animations
              asset/activities/drug_action/animations
              asset/activities/drug_action/animations
              end_slide
              Various pills and tablets
              Science Photo Library/Getty Images
              Congratulations!
              You have completed the activity How Do Therapeutic Drugs Work?