Lecture 19 Flashcards
____ is a potential for drug-receptor binding
Affinity
____ is a binding site with biological effect.
Receptor
This deals with the capacity to produce a biological effect
Intrinsic activity
These are substances that stimulate a receptor to produce a physiologic reaction and have intrinsic activity and affinity
Agonist
These are substances that oppose with the activity of a receptor and its endogenous substrate without producing a physiologic effect itself.
Antagonist
Antagonists have ____ but lack
affinity; intrinsic activity
What is the equation for efficacy
affinity x intrinsic activity
What does EC50 stand for. Where is it tested?
Effective concentration in 50% of subject. Tested in labs
What does ED50 stand for? Where is it tested?
Effective dose in 50% of subjects. More real world..tested in doses
What results in chronic antagonism
Hypersensitivity
This refers to a minimum amount of drug producing a maximum therapeatic effect
Maximum dose
a partial agonist has ____ intrinsic activity with potency and affinity within therapeutic range.
low
Pharmacodynamics deals with ____ on ____
drug; body
Pharmacokinetics deals with ____ on ____
body; drug
Potency is ____ related to EC50 for ____
inversely; agonists; The lower the EC50, the higher the potency
Potency is inversely related to ______ for drug antagonists
IC50; The lower the IC50, the higher the potency
What refers to the science of drug dosing
Posology
What is a biological response to a given dose
Potency
This deals with loss of pharmacological effect
Resistance
This is the ability to produce a desired effect vs adverse effect
Selectivity
This is the ability to act a specific receptor
specificity
This refers to rapidly decreasing therapeutic response
tachyphylaxis
This deals with congenital malformation
teratogenesis
This is the amount of active drug reaching target tissue
bioavailability
_____ therapeutic indices are the safest
High
______ explains side effects. Lack of this deals with complications that has nothing to do with the region your targeting
Specificity
What are the six drug types
- Supplemental; normally produced in body but in low amounts
- Supportive: Helping pts cope with symptoms rather than cure
- Symptomatic: Pt goes in with symptom and is looking for a relief
- Diagnostic: No therapeutic benefit.
- Therapeutic: Pt’s are looking for a cure
- Prophylactic: Protect
What are the different types of receptor motifs
- Nuclear: steroids, hormones
- G protein coupled: AChm, rhodopsin
- Ion channels: GABA, glutamate, AChn
- Enzymatic: insulin, epidermal growth factor
- Calcium release: nitric oxide synthase
What are the different types of agonists
- Direct: isoproterenol
- Indirect: cocaine
- Partial: Buspritone
- Mixed: Tamoxifen
- Inverse: Ro1545
____ _____ don’t produce full biological effect. They demonstrate less dependency and withdrawal effects
Partial agonists
What are the types of binding selectivity for antagonists
- Competitive
- Non competitive
- Uncompetitive
Describe non competitive antagonists
Not competing for same site as agonists; it has its own binding site and it doesn’t matter if agonist is available or not its a matter of who reaches site first.
Describe uncompetitive antagonist
Requires the presence of an agonist
What is absorption influenced by
- first pass metabolism
2. patients age, gender, weight, pregnancy, health
What is volume of distribution
dose/drug in plasma
*influenced by route of administration
what is drug clearance
drug volume eliminated + time
What does a high volume of distribution mean
The drug does not readily remain in the bloodstream; which can expose patients to toxicity.
What does dehydration cause
A low volume of distribution because the lower plasma volume artificially enhaces drug plasma concentration
____ ____ is where there is a free exchange of substances into blood vessels that are close to mucous membranes.
mucous membranes
What are two key barriers to drug passage in the eye
RPE and corneal epithelium
What is the site of greatest administration of drugs administered topically
ciliary body
What are ocular drug barriers
- Tear film
- Cornea
- Conjunctiva and sclera
- Iris
Cornea and conjunctiva have outer ____ charges
negative
A dark iris is more ____
lipophilic; require more drops bc of more pigment and lasting effect is bound to be more sustained
Basal tear flow ranges from ____ to _____ul/min
0.5 = 2.2
If you have 10 ul of tear film on eye how long does it take to replenish that?
20 mins. 10/0.5
Entire tear volume is replaced between ____ and 20 mins
5
Normeal tear pH is around ___ to ___
7.1-7.6 (slightly basic)
A charged state _____ metabolism
reduces
Charged drugs accumulate in _____ media
aqueous
What are some drug barriers in the eye
- Anterior chamber aqueous humor
- Crystalline lens
- Ciliary body
- Vitreous
- Blood retinal barrier
Chroidal and ____ blood flow is responsbile for bringing systemic drugs into the eye.
uveal
____ order is concentration independent. There is constant amount of clearance. Elimination per unit time is ____
Zero; linear
Most drugs are ____ order and they are concentration ____. There is a ____ ____ carrier. There is a constant proportion of ____ and constant ____ ___. Elimination per unit time is ______.
First; dependent; non saturable; clearance; half life; exponential
____ order means there is a saturable carrier at high concentrations only
Mixed
