Pharmacodynamics Flashcards
Pharmacodynamics =
How the drug affects the body
Pharmacokinetics =
What the body does to the drug
Pharmacodynamics is the study of-
Drug concentration and it’s effects on the body
Pharmacodynamic Phase=
When a drug reaches its site of action and produces an effect
Most receptors are found on-
Cell membranes
What do drugs act through to produce or block a response?
Receptors
Agonist =
Produces a response
Antagonist =
Blocks a response
Drugs with a better fit for a receptor will produce a stronger response.
True or false?
True
Isoproterenol (Isuperel) stimulates B1 receptors. This is an example of a-
Agonist
Cimetidine (Tagamet) blocks the H2 Receptor. This is an example of a-
Antagonist
The ability of a drug to bind to a specific receptor is determined by-
The nature of the drug
Drug binding to receptors is like a-
Lock and key mechanism
Po =
Always less than 100%
IV =
Always around 100%
Bioavailability is determined by-
Cumulatively measuring drug concentration in bodily fluids over time.
Bioavailability is affected by-
Drug form, route, presence of food/ other drugs, GI motility, liver metabolism
Affinity describes-
The relative strength of a drug’s binding to receptors
Drugs with a greater affinity for particular receptors are-
capable of eliciting a response at lower doses
Drugs with a lower affinity for particular receptors are-
Less strongly attracted to the receptors and require a larger dose to elicit a response.
Potency=
Dosage needed to produce a response
Efficacy =
The degree to which a drug is able to produce its maximal effects
How can you tell of a drug is more efficacious than another drug?
By comparing the maximal dose effects. A drug with more significant effects at it’s maximum is more efficacious.
The Therapeutic Index is a-
Measure of safety