MSN 526 Pharmacology
Module 1 Study Outline
1. Define pharmacodynamics
Dynamics = action
vs. kinetics= movements
Pharmacodynamics is how the drug actually works. This means on the biochemical level, how is
the drug working. What the side effects?
Pharmacokinetics is how the drug moves through the body from
how it enters the body, how it reaches the site of action, how it is
metabolized, and how it is eliminated.
the generic name, chemical name, and trade names of drugs.
Generic name of a drug is the chemical name of the
Chemical name is the scientific names of the molecular structure
of the drug.
Trade name is the trademark name or commercial
trade name by the company that holds the
patent for that specific drug.
3. What is the
significance of bioavailability and bio-equivalence? Give examples of differences.
Bioavailability is the measurement of the amount of drug
absorbed in the body. Bioavailability is
the degree and rate of
the drug absorbed by the body’s circulatory system.
Bio-equivalence is a comparison of two or more products with respect
to their bioavailability/absorption.
are determined in clinical trials by phase 1 and 2 clinical trials o to
4. List three
common drug-food interactions that you were not aware of?
A food-drug inter action can prevent a medicine from
working in the way it should, cause a side effect or cause a new side effect .
Calcium-Rich Foods and
Dairy products (i.e milk, yogurt, and cheese) can interfere with antibiotics
such as tetracycline, doxycycline, and ciprofloxacin.
These antibiotics may bind to the calcium forming an insoluble substance in the
stomach and make body unable to absorb the antibiotic.
Pickled, Cured, and Fermented
Foods and MAIOs
Tyramine rich foods can increase blood pressure among patients taking monoamine
oxidase inhibitors (MAIOs) and certain medications for Parkinson’s disease.
Vitamin K-Rich Foods and Warfarin
Taking warfarin to maintain a consistent intake of vitamin K and avoid
introducing kale, spinach, and other leafy greens to their diets.
Vitamin K produces clotting factors that help prevent bleeding, but
anticoagulants like warfarin exert their effect by inhibiting vitamin K. An
increased intake of vitamin K can antagonize the anticoagulant effect and
prevent Warfarin from working.
5. Compare active
transport vs. passive diffusion.
Active transport is the process of moving a molecule or ion against
the concentration gradient using energy (ATP),
across a plasma membrane.
Passive diffusion is when small molecules diffuse
across a cell membrane from a region of high concentration to one of low
6. How does
distribution of drugs through the CNS differ from other systems?
Drugs pass the blood brain barrier (BBB) by trans membrane
diffusion. Fat-soluble substances pass
through the BBB while water-soluble substance has difficulty passing
through. The BBB is selective by solubility
factors of drugs. Drugs must pass through cells
rather than between them. Only drugs that have a high lipid-water partition
coefficient can penetrate the tightly apposed capillary endothelial cells.
7. Explain the
P450 cytochrome system.
The P450 cytochrome enzyme system is primarily
responsible for the metabolism (degradation and elimination) of drugs and primarily found in liver cells.
8. What is the
first pass effect? Give an example when this is important.
The first pass effect is when the concentration of a drug is
reduced greatly before it reaches circulation due to the absorption first in
the gut and liver thus reducing it’s overall effectiveness.
An example is Morphine-~30%
Bioavailability because 70% is metabolized via 1st pass effect if taken orally.
The drug is absorbed from the GI tract
and passes into the liver where some drugs are metabolized. Only a proportion of the drug reaches the
9. What is half
life? What is steady state? Why do these
Half-life is the time taken for the plasma
concentration of a drug to reduce to half its original value.
For example the half life of Adderall
is about 10 hours. For every 10 hours, half of the previous amount
of Adderall in the body disappears. IF 10mg of Adderall was taken at 12AM
(midnight), at 10AM 5mg of Adderall will be left in the body.
Steady state is when the overall intake of
is in dynamic equilibrium with its elimination.
The time taken to reach the steady
state is about five times the half-life of a drug. Maintenance medications must be taken to
insure a steady state is kept in place.
10. Define the
therapeutic window and index.
Therapeutic window is the
range of doses of a drug that produces an effective response without being
harmful or causing any significant adverse effects.
Therapeutic index is a ratio that compares the blood
concentration at which a drug becomes toxic and the concentration at which the
drug is effective. The larger the therapeutic index (TI), the safer the drug
is. If the TI is small (the difference between the two concentrations is
very small), the drug must be dosed carefully and the person receiving the drug
should be monitored closely for any signs of drug toxicity.