Chapter Three
Summary
In Chapter Three we explored the concepts of psychodynamics or how drugs affect the body, i.e., receptor
cites and how they cause neurochemical changes in the body. Pharmacokinetics refers to the drugs administration,
absorption, distribution, metabolism, and elimination, i.e., how the body affects the drug. We outlined nine routes of
drug administration including, oral, subcutaneous, IM, intradermal, intranasal, inhalation, sublingual, transdermal,
and IV. We also explored several drugs that offer various routes of administration.
We explored the concept of first pass and protein binding. We also covered the concepts of half-lives and
lipid solubility, as well as liver clearance and the P450 family of enzymes.
Therapeutic index and therapeutic dose were discussed using lithium as an example.
Loading doses may be needed to introduce the drug and its therapeutic effects as quickly as possible.
Specific Discussion Questions:
1. How does lipid solubility affect whether a drug will exert its effects on the brain and central nervous system?
2. Explain how drugs are metabolized in the liver by P450.
3. Explain the concept of a drug’s half-life.
4. Explain the importance of knowing about a drug’s therapeutic index.
5. Explain the principles of tolerance and withdrawal. How is this different or the same as discontinuance
syndrome?
6. How do drugs affect each other in terms of synergism or potentiation?
7. Build a case for familiarity with various pharmacy terms and abbreviations.
Possible True/False Questions:
1. Zyprexa is available as an orally dissolving tablet.
2. There were eight routes of administration discussed in this chapter.
3. Pharmacodynamics is the study of how drugs affect receptor sites, send signals, and cause neurochemical
changes.
4. Intranasal was one of the mentioned routes of administration.
5. Some medications like Haldol and Risperdol Consta are available as an IM preparation.
6. Absorption of most oral medication takes place in the small intestine.
7. Some gastrointestinal diseases and treatments interfere with drug absorption.
8. Drug protein binding may hinder a drug’s metabolism and cause the drug to remain longer in the circulatory
system.
9. Geriatric patients and others with decreased liver enzyme activity may require lower doses of medications to
avoid toxicity.
10. Synergism refers to the effect that happens when one drug cancels the other drug out.
11. P.R.N. is a Latin abbreviation for “as needed.”
12. t.i.d. stands for “twice a day.”
Possible Multiple Choice Questions:
1. Routes of drug administration include all of the following except:
a. oral
b. Intravenous
c. intranasal
d. intercerebal
2. Half-life refers to:
a. The average time required to eliminate one half of the drug’s concentration.
b. The amount of time needed to eliminate the entire drug from the body.
c. The amount of time needed to notice the drug’s effectiveness.
d. None of the above.
3. Therapeutic index refers to:
a. The difference between half-life and therapeutic ranges.
b. The difference between side effects levels and toxicity.
c. The difference between a drug’s desired concentration and toxicity.
d. The difference between effectiveness of two like medications.
4. Introducing a higher level of a medication to obtain a desired response is known as:
a. depot binding
b. loading dose
c. vital dose
d. titrating dose
5. All of the following are symptoms of drug withdrawal except:
a. euphoria
b. insomnia
c. tremors
d. seizures
6. When one drug significantly enhances the action of another, this is known as:
a. potentiation
b. maximization
c. synergism
d. interaction
7. Placebo effects are actually:
a. not noticed with most medications
b. The mind playing tricks on the patient
c. Real physiologic changes to the brain and body.
d. None of the above
8. In reading the following prescription in a medical record–Xanax .5 mg b.i.d. or p.r.n would mean:
a. Xanax .5 mg with food as needed.
b. Xanax .5 mg three times per day or before bedtime.
c. Xanax .5 mg twice a day or before meals.
d. Xanax .5 mg twice a day or as needed.
9. Tolerance usually leads a client to:
a. decrease the amount of a drug that is used/abused.
b. stop using/abusing the drug.
c. increase the amount of a drug used/abused.
d. change to a different drug.
10. Discontinuing most psychotropic medications, like antidepressants, may result in:
a. death
b. seizures
c. blood disorders
d. flu like symptoms
Alternative Class Assignments and Essay Questions:
1. Have students review the various routes of drug administration and decide if some would be better or worse
for patient compliance.
2. Have students make a list of all legal and illegal drugs that have been known to lead to tolerance.
Demonstrate how clinicians would assess for this per the DSM-IV criteria.
3. Using a particular medication, have the students calculate how many half-lives it would take for that
medication to be eliminated from the body.
4. Have students explain why a working knowledge of the therapeutic index is key for patients taking lithium.
Chapter Three
Answer Key
True/False Questions
Multiple Choice Questions: