Pharmacodynamics and Adverse Effects Flashcards
What is pharmacodynamics?
The study of what drugs do to the body and how they do it
What is a therapeutic effect and why is that the goal?
It’s a positive change in a faulty physiological system
Why do we need to know pharmacodynamics?
We as nurses must be able to EDUCATE our patients, make PRN DECISIONS, be able to EVALUATE our patients and COMMUNICATE with prescribers
What determines the MEC of a drug?
The dose-response relationship
What determines the maximum response a drug can elicit?
The dose-response relationship
What determines toxic level
The dose-response relationship
What are you thinking about when you decide to increase the dosage to produce an increase in response?
The dose-response relationship
As a dose increases does the response increase or stay the same?
It increases
How do you find the desired intensity of response?
You start with a dose and change it up or down till you find the right amount
What is maximal efficacy?
The largest effect that a drug can produce (the peak)
What may happen if a drug’s maximal efficacy is very high?
It could become toxic
Why is the relative potency not an important characteristic?
Only important when a lack of potency forces inconveniently large doses
What are drugs?
Chemicals that produce effects by interacting with other chemicals
What are receptors?
Special chemicals in the body that most drugs interact with to produce effects
What does every cell have that receives a signal to elicit a response?
Receptors
What is a receptor?
A receptor is any functional macromolecule in a cell to which a drug binds to produce its effects
What do receptors normally receive signals from?
Hormones, neurotransmitters, and other regulatory molecules
What are the body’s normal points of control?
Receptors
Under physiologic conditions, what are receptors functions regulated by?
Molecules supplied by the body
What are the only two things drugs can do to the body?
Mimic or block the regulatory molevules
T/F Can drugs give cells new functions?
NO
What are receptor interactions?
The joining of the drug molecule with a receptor site on the surface of a cell or tissue
What is affinity?
The degree of attachment and binding, how much it wants the receptor
What are enzyme interactions?
Either inhibits or enhances the action of a specific enzyme
What is a nonselective interaction?
The drug does not interact with a receptor or enzyme
What is an agonist?
A drug that does the same action as an enzyme, there is a response
What is a partial agonist?
A drug that does the same thing as an enzyme but to a lesser extent
What is an antagonist?
A drug that blocks enzymes, there is no response
What are endogenous regulators (hormones) considered? Agonists or antiagonists?
Agonistis
Do adonists have affinity and intrinsic activity?
Yes and yes
Do antagonists have affinity and intrinsic activity?
Yes and no
Is morphine an agonist or antagonist?
Agonist
Is naloxone (Narcan) an agonist or antagonist?
Antagonist
What is the pharmacologic effect of an antagonist?
They prevent the activation of receptors by agonists
If there is no agonist will the antagonist have an observable effect?
No
What do noncompetitive antagonists do?
Bind IRREVERSITBLY, REDUCE the max response that an agonist can elicit (fewer receptor spots)
What do competitive antagonists do?
Bind REVERSIBLY, have equal affinity with agonists
Why is it that the more a cell tolerates a drug the less responsive it is?
The number of receptors on the cell surface and the sensitivity to agonists can change
When a drug binds to a receptor will it increase or decrease the rate of physiologic activity normally uncontrolled by that receptor?
Both