Chapter 5 Flashcards
The study of biochemical and physiologic effects of drugs and molecular mechanisms by which those effects are produced. (how drugs work once they’re in the body)
Pharmacodynamics
Define dose-response relationship
the relationship between the size of an administered dose and the intensity of the response produced
Dose-response relationships determine:
- the minimum amount of drug needed to elicit a response
- the max response a drug can elicit
- how much to increase the dosage to produce desired increase in response
the largest effect that a drug can produce
Maximal Efficacy
the amount of drug we must give to elicit an effect
Potency
___ is rarely an important characteristic of a drug
potency
the potency of a drug implies nothing about its ___ ___
maximal efficacy
the only way drugs can produce their effects is:
interacting with other chemicals
Drug-receptor interactions:
*receptors are chemicals in the body that the drug must find to have its effect
Drug+Receptor –> drug-receptor complex forms–> response
the more selective a drug is, the ______
fewer the side effects
if a drug interacts with only a few receptors –>
if a drug interacts with many receptors –>
limited drug response
wide variety of responses
just because a drug is highly selective, doesn’t mean that it’s ___
safe
the more receptors that are occupied by drug will create —>
a more intense effectiveness of that drug
what will occur when all receptors are occupied?
maximal response
bind at low doses, making them very potent
High affinity
bind at higher doses, making them weak or not a potent drug
low affinity
molecule that activate receptors
Agonists
- can have many effects, not always necessarily making body processes faster
produce their effects by preventing receptor activation by endogenous regulatory molecules and drugs
Antagonists
receptor-less drugs
don’t need a receptor to activate
EX: antacids, antiseptics, laxatives, chelating agents.
initial doses are __ while later doses are ______
approximate
adjusted as needed to treat the pt
doses are adjusted based on:
how the patient responds to the drug
Therapeutic index
- measure of a drug’s safety
- the ^ the index, the safer the drug
- drugs with low therapeutic index are as equally effective as they are harmful.
