IM1- Pharm 2 quiz Flashcards
What is pharmacokinetics?
How a drug moves through the body
What are some questions that should come to mind when thinking in terms of pharmocokinetics?
- How does the drug get into the body and where does it go?
- What does the body do to/with the drug?
- How does the body get rid of the drug?
What is the process of a drug through the body?
- absorption
- distribution
- metabolism
- excretion
True or false: different drugs are metabolized by different organs?
True
True or false: the majority of drugs are metabolized by the liver
True
Where are the majority of drugs excreted?
Kidneys
What is absorption?
The movement of a drug from its site of administration into the blood
In pharmacology rate is determines what?
How soon a drugs effects will take place
In pharmacology amount determines what?
how intense the drugs effects will be
Name 6 factors that affect the process of absorption.
- Rate of dissolution
- surface area
- blood flow
- Lipid solubility
- pH partitioning
- Route of administration
True or false: With rate of dissolution the quicker a drug dissolves the slower the effect will be?
False
True or false: With surface area the larger the surface area the quicker the drug is absorbed
True
True or false: Our body prefer drugs that are lipid soluble because it is easier for them to enter our blood stream.
true
What are the two major groups in routes of administration?
Enteral (gastrointestinal GI tract)
Parenteral (outside of the GI tract)
Is oral meds considered enteral or parenteral?
enteral
Is IV, subQ and IM considered enteral or parenteral?
Parenteral
What are the advantages to PO meds?
- Safer than injections
- ideal for self-administration
- easy, convenient and inexpensive
What are the disadvantages to PO meds?
1.Can cause GI irritation
2. Requires cooperative patient
3. Inactivation
4. Varibility
What are some barriers to absorption with PO meds?
- Epithelial lining of GI tract
- capillary wall
What is the absorption pattern for PO meds?
Slow and variable
True or false: no one patient absorbs the drugs the same
true
What are some advantages of IV drugs? List 4
- Rapid onset
- Control
- permits use of lg fluid volumes
- permits use of irritant drugs (chemo drugs)
What are some disadvantages of IV drugs? List 4
- High cost, difficulty, inconvenience
- irreversibility
- infection
4.high risk
What are the barriers of absorption for IV drugs?
None goes directly into blood stream
What is the absorption pattern for IV drugs?
Instantaneous and complete
What are the advantages of IM and subQ drugs?
1.Can be used for poorly soluble drugs
2. Can be used for depot preparations
What are depo preparations?
One time injection that last over a period of weeks to months
What are some disadvantages to IM and subQ drugs?
list 4
- discomfort
- inconvenience
- can cause muscle and nerve injury with improper technique
- bleeding risk
What are the barriers of absorption for IM and SubQ drugs?
None
What is the absorption pattern for IM and subQ drugs?
Water solubility
blood flow
When is parenteral administration preferred?
- emergencies
- situations requiring tight control
- GI incompatibility
- destruction of drugs by GI system
- drugs that would cause GI injury
- tx with drugs that cannot cross membranes
- condition better treated with long-acting preparation
- patients who cannot or will not take oral preparation.
True or false: if a patient is having a life threatening issue the best route of administration is the enteral administration
False
What is distribution?
The movement of drugs through the body
Review the distribution process on slide 15 on the pharm 2 lecture
review
What is drug metabolism?
The enzymatic alteration of drug structure to a more water-soluble form that can be excreted.
What are some special factors/consideration in drug metabolism?
- age- the very young and very old have a decreased metabolism
- first-pass effect- some meds are totally metabolized by the liver the first time they pass through
- Nutrional status
- competition between drugs. - One drug may commpletely neutralize the other
What is excretion?
the removal of drugs from the body
Drugs and their metabolites can exit the body through…..
- bile
- urine/feces
3.sweat/saliva - breast milk
- expired air
What is plasma drug levels?
Correlation between the response to a drug and level in plasma
What are two important levels in monitorying of drug responses?
- MEC- Minimum effective concentration
- Toxic concentration
What is the therapeutic range when monitoring drug responses?
Determines whether the drug can be safely given
When monitoring drug responses what does drug- half life mean?
Determines dosing intervals
Define drug half-life
Defined as the time required for the percentage of a drug in the body to decrease by 50%.
Why is it important to understand a drugs half-life?
So we understand how often a patient needs to take a drug
When monitoring drug responses what is repeated dosing mean?
Determines rate and extent of accumulation
In repeated dosing what does peak mean?
Highest level of drug in the body–> normally peak of a drug is one to two hours after a dose
In repeated dosing what does trough mean?
Lowest level of drug in the body–> usually just before the next dose
What is a loading dose?
Its a higher dose to get blood levels of the drug up then taper to get a maintenance dose or everyday dose. Example is a zpack.
What is pharmacodynamics?
It is the affect a drug has on the body
What is dose-response relationship?
Relationship between the size of a an administered dose and the intensity of the response produced
True or false: the more drug you give the more affects you should have?
True
What is ED50
Stands for average effective dose. Typically the standard dose we use when starting a patient on a med
What is LD50?
Lethal dose in 50% of test animals
What does the dose-response relationship tell us?
It determines
- Relative potency- min amount of a drug needed to elicit a response
- maximum efficacy- max response a drug can elict
Understand the therapeutic index
Take time to review slide 28 on the pharm two power point
True or false: we want to have a very wide range between the effective dose and the lethal dose?
True
True or false: The narrower the space between the effective dose and lethal dose the safer the drug?
False- the wider the space the safer the drug
What does the TI or therapeutic index tell us?
Allows us to know how wide of an index we have to work with when administering does of meds.
What are three possible drug to drug interactions?
- Potentiate
- inhibit
- new response
What is potentiate?
Intensifies the effects of two or more drugs
What is inhibit mean when talking about a drug to drug interaction?
reduce the effects
What is a new response drug to drug interaction?
Effect not seen with single drug alone
What does it mean to have an empty stomach?
At least 1hr before or 2 hours after a mean
What are some drug-food interactions?
- absorption
- drug metabolism
- drug toxicity
- drug action
- timing