How does Canada's schedule of drugs differ from the U.S.'s?
3 drug schedules.
I: all prescription drugs
II: all nonprescription drugs monitored for sale by pharmacists.
III: all nonprescription drugs NOT monitored for sale by pharmacists.
Addiction
overwhelming feeling that drives a person to use a drug repeatedly despite its negative health and social consequences.
Dependence
a strong physiologic or psychologic need for a substance.
What are the 5 rights of drug administration?
1. Right patient
2. Right medication
3. Right dose
4. Right route of administration
5. Right time of delivery
What are the 3 checks of drug administration?
1. check the drug with the MAR when retrieving.
2. check the drug when preparing it.
3. check the drug BEFORE administrating it.
Compliance
Taking medication in the manner prescribed. Includes: time, route, dosage.
STAT order
given within 5 minutes, given only once
ASAP order
given within 30 minutes, given only once
Single order
given only once at a specific time
Ex: STAT, ASAP
PRN order
given as the patient needs it
standing order
written in advance of a situation, carried out under specific circumstances.
allergic reaction
an acquired hyper-response of the body's defenses to a foreign substance. Varies in severity.
What is the nurses job for allergic reactions?
alert all personnel by documenting the allergy in the patient's medical record; labeling the patient's medical record and MAR record.
What are the 3 main routes of drug administration?
1. enteral
2. topical
3. paraenteral
What are the 4 main methods of enteral drug administration?
1. tablets, capsules, and liquids
2. sublingual
3. buccal
4. nasogastric and gastric tubes
What is a main consideration of administering medications enterally?
The medications will go through first pass metabolism.
What forms of enteral administration do not go through first pass metabolism?
sublingual and buccal
What are the main ways to administer a medication topically?
1. creams, lotions, or gels
2. transdermal patches
3. optic drops and ointments
4. otic drops and irrigations
5. nasal drops and sprays
6. vaginal suppositories, creams, jellies, or foams.
7. rectal suppositories and enemas.
Do topical medications go through first pass metabolism?
No, they are absorbed through the skin or mucous membranes.
What are the primary routes of parenteral drug administration?
1. intradermal
2. subcutaneous
3. intramuscular
4.intravenous
When would you typically give an intradermal injection?
allergy shots, disease (PPD) screening, or local anesthetic delivery
When would you typically give a subcutaneous injection?
insulin shots, heparin shots, vaccines and other medications
What are the three main ways of giving an IV?
1. large volume infusion - typically for fluid replacement/maintenance.
2. intermittent infusion (aka tandem or piggyback IV) - to instill adjunct medications over a short period of time.
3. IV bolus (push) administration - to deliver a concentrated does directly to the circulation by syringe one-time.
Pharmacokinetics
The study of drug movement throughout the body.
What are the 4 categories of pharmacokinetics?
1. absorption
2. distribution
3. metabolism
4. excretion
What is absorption?
The process of moving a substance from its site of administration, across body membranes, to circulating fluids.
It is also the primary factor in determining how long it takes a drug to produce its effect.
Active transport
movement of a chemical against a concentration or electrochemical gradient.
Passive transport (diffusion)
movement of a chemical from an area of higher concentration to an area of lower concentration.
Factors that affect absorption
pill vs liquid
route of administration (IV quickest)
blood flow
dosage
enzymes in digestive tract
speed of digestive motility
degree of ionization
drug-drug or drug-food interactions
distribution
the transport of pharmacologic agents throughout the body
blood-brain barrier
fetal-placental barrier
anatomic barriers that prevent many chemicals and medications from entering
drug-protein complex
some drugs have an affinity for binding to plasma proteins. Once these drugs bind to a protein, they are tied up and unable to reach their target cell. Only unbound drug molecules can reach their target cell or be excreted by the kidneys.
metabolism (biotransformation)
process of converting a drug to a form more easily removed from the body. Primarily the job of the liver.
prodrugs
drugs that have no pharmacologic activity until they are metabolized
first pass metabolism
drugs that enter the bloodstream through the stomach or small intestine, must first pass through the liver before they are distributed. Much or the drug will be metabolized as it passes through the liver.
excretion
the process through which drugs are removed from the body
What is the primary site of excretion?
the kidneys
How can we measure the therapeutic response of most drugs?
By seeing how much drug is in the plasma.
minimum effective concentration
the amount of drug required to produce a therapeutic effect
toxic concentration
the level of drug that will result in serious adverse effects
therapeutic range
the plasma concentration level between the minimum effective concentration and the toxic concentration.
plasma half-life (t1/2)
length of time required for the plasma concentration of a medication to decrease by one-half after administration.
T or F
USP is an official lexicon for drug quality standards in the United States.
True
T or F USP was formed as a private enterprise in 1820 with no government authority or oversight.
True
Who signed off on the Pure Food and Drug Act?
President Theodore Roosevelt
What year was the Pure Food and Drug Act signed?
1906
What was the main provision to come out of the Pure Food and Drug Act?
created a prescription drug category
What was the primary impetus behind the Pure Food and Drug Act?
Upton Sinclair's "The Jungle"
In what year was the Harrison-Narcotics Act enacted?
1914
For what purpose could physicians prescribe narcotics?
medical purposes only
pharmacodynamics
how a medicine changes the body
median effect dose (ED50)
the dose required to produce a specific therapeutic response in 50% of a group of patients
median lethal dose (LD50)
the dose of the drug that will be lethal in 50% of a group of animals
therapeutic index
ratio between LD50 and ED50. The higher the value the larger the margin of safety.
median toxicity dose (TD50)
the dose that will produce a given toxicity in 50% of a group of patients.
potency
a way to compare medications within the same therapeutic or pharmacologic class. A more potent drug will produce a therapeutic response at a lower dose.
efficacy
magnitude of maximal response produced by a drug (how well it works).
which is more important efficacy or potency?
efficacy is more important
How do drugs act?
They bond to a receptor that then changes or modulates the existing physiologic and/or biochemical process.
Agonist
a drug that produces the same type of response as the endogenous substance. It mimics the body's natural response.
Antagonist
a drug that prevents the endogenous chemical from acting. Often competes with agonists for the receptor binding site.
idiosyncratic responses
unpredictable and unexplained drug reactions
pharmacogenetics
the area of pharmacology that examines the role of heredity in drug response.
