Directions
Answer the following study guide quesons to help guide you in your learning for this week’s topic(s).
Your answers must be written in your own words, paraphrasing what you have learned from your
research. Include in-text citaons with each response and then full references at the boom in current
APA professional paper format.

1. On the drug concentration curve, what is the first sign of a therapeuc effect?
2. Describe the purpose of the blood-brain barrier and the fetal placental barrier.
3. What is the dierence in distribuon for each medicaon route?
4. How will renal insuciency aect drug eliminaon?
5. Describe the eects of drugs based on the route of administraon.
6. Describe the role of the isoenzymes.
7. According to the WHO, what are the steps in the prescribing process?
8. What does the FDA have the authority to approve?
9. What is o-label prescribing?
   What to Submit
   Your answers in a MicrosoWord or PDF document
   In-text citaons and full citaons on a reference page
   If you use a textbook, include the page number or numbers you consulted to respond to the
   queson. This will allow you to easily locate the informaon later.
   If you copy and paste references from the course into your assignment, be sure to conrm current APA

SAMPLE ANSWER

Study Guide Questions 2
First Sign of Therapeutic Effect

The first sign of therapeutic effect on the drug concentration curve is observed as an
increase in the drug’s concentration in the bloodstream. An increase in drug concentration in the
bloodstream indicates that the drug is starting to take effect toward achieving the desired
outcomes.

Blood Brain Barrier and the Fetal Placental Barrier

The purpose of the blood-brain barrier is to allow the movement or exchange of
molecules to and from the brain and the bloodstream. Fetal-placental barrier, on the other hand,
allows the regulation of material transfer between the mother and the fetus through blood
circulation for the development and maintenance of the homeostatic balance of the fetus (Zhao et
al., 2022)

Differences in Distribution for Each Medication Route

Different routes of administration have different modes of distribution in the body. For
oral medication, the mode of distribution is through the GI tract and then the bloodstream to
other body organs and tissues. For IV administration, the route of distribution is directly through
the bloodstream to the target organs. For topical medication, the mode of distribution is through
the skin and usually has a localized effect with marginal systemic distribution. Inhaled drugs are
distributed from the lungs, where they are readily absorbed into the bloodstream for systemic
circulation. For IM medication, they are slowly absorbed from the muscle tissue into the
bloodstream for systemic circulation to the target site.

How will Renal Inefficiency Affect Drug Circulation

STUDY GUIDE QUESTIONS 3
Renal inefficiency may lead to ineffective filtration of the drugs, leading to higher
concentration and half-life of particular drugs in the bloodstream.

Effects of Drugs Based on Their Route of Administration

Different routes of administration have different implications on the effect of drugs. For
example, drugs taken through the oral route have a reduced onset of action compared to IV-
administered drugs that require controlled dosage with an almost instantaneous onset of action.
Additionally, the route of administration also impacts mostly the target area in which the drug is
administered. For example, in inhaled drugs, the site of action is usually the respiratory organs.

Describe the Role of Isoenzymes

Isoenzymes have an important role to play in the synthesis of certain hormones and body
fluids, which determine the pharmacokinetic behavior of certain drugs.
Steps in the Prescribing Process

The WHO process of rational prescribing involves six major steps, which include
defining the patient’s problem, specifying the therapeutic objective for prescribing, establishing
whether the personal treatment regimen is the best option for the patient, starting the
prescription, educating the patient about the indications and warnings associated with the drug,
and finally monitoring whether the prescription is effective and if there are any side effects to be
wary of (Rongen et al., 2021).

What Does the FDA have the Authority to Approve?

The FDA has the authority to approve any drugs and biologics for both humans and
animals, including medical devices to ensure that they are safe for use.

Off Label Prescribing

STUDY GUIDE QUESTIONS 4
Off-label prescribing involves prescribing medication to treat a condition that is different
from what it was indicated for or stated in its license (Van Norman, 2023).

STUDY GUIDE QUESTIONS 5

References

Rongen, G. A., Marquet, P., van Gerven, J. M. A., & EACPT research working group. (2021).
The scientific basis of rational prescribing. A guide to precision clinical pharmacology
based on the WHO 6-step method. European Journal of Clinical Pharmacology, 77, 677-

683. https://doi.org/10.1007/s00228-020-03044-2
     Van Norman G. A. (2023). Off-label use vs. off-label marketing of drugs: Part 1: Off-label use
     patient harms and prescriber responsibilities. JACC. Basic to Translational Science, 8(2),
     224–233. https://doi.org/10.1016/j.jacbts.2022.12.011
     Zhao, Q., Dai, W., Chen, H. Y., Jacobs, R. E., Zlokovic, B. V., Lund, B. T., Montagne, A., &
     Bonnin, A. (2022). Prenatal disruption of blood-brain barrier formation via
     cyclooxygenase activation leads to lifelong brain inflammation. Proceedings of the
     National Academy of Sciences of the United States of America, 119(15), e2113310119.
     https://doi.org/10.1073/pnas.2113310119