Intro Flashcards
Which type of drug permeation is not governed by Fick’s Law and is capacity limited?
Transport by special carriers
Ionized and polar drugs are more _____ soluble and with ______ clearance
Water soluble
Increased clearance
Absorption is faster with:
_____ surface area and ____ membranes
Larger surface area and thinner membranes
What predicts the rate of movement of molecules across a barrier?
Fick’s law of diffusion
Which quadrant of the buttocks if the safest for IM drugs?
Superolateral
Through which blood vessels do sublingual drugs pass?
Lingual vein– IJV– brachiocephalic– SVC– right atrium
What route has a partial avoidance of the first pass effect?
Rectal
What route offers the closest delivery to the target in respiratory diseases?
Inhalational
Which route of administration is the slowest?
Topical
Arrange topical route from more evaporation to less:
Tincture Wet dressings Lotion Gel Aerosol Powder Paste Cream Foam Ointment
4 factors that determine drug distribution:
Organ size
Blood flow
Solubility
Protein binding
Influences the concentration of the drug in the extracellular fluid surrounding the blood vessel
Solubility
Acidic drugs are bound to this protein
Albumin
Basic drugs bind to this protein
Orosomucoid
A1 acid glycoprotein
What protein binds NT and hormones?
Globulin
Type of drug metabolism where the drugs are metabolized into biologically inactive derivatives
Termination of drug action
Drug metabolism where prodrugs are metabolized to become active
Drug activation
Metabolism:
Some drugs are not modified by the body and continue to act until they are excreted
Elimination without metabolism
Give examples of drugs that undergo elimination without metabolism
Mannitol
Lithium
Electrolytes
Duration of drug action is determined by
Dose administered
Rate of elimination following last dose
This is the most common type of elimination
First order elimination
This type of elimination is proportionate to the concentration
First order elimination
Constant fraction is being eliminated over time
First order elimination
Rate of elimination is constant regardless of concentration
Zero order elimination
Concentration in zero order/saturable/michealis menten decreases ______ over time
Linearly
Drugs that display Zero Order Elimination kinetics?
WHAT PET
Warfarin Heparin Aspirin Tolburamide Phenytoin Ethanol Theophylline
It is the maximal effect available with increasing concentration of a drug
Efficacy (Emax)
It is the dose required to produce 50% of the max effect
Potency (EC50)
Concentration required to bind 50% of the receptors
Kd
Smaller the Kd, the ____ the affinity
Greater
Maximum percentage of receptors with increasing concentration of a drug
Maximal number of receptors bound
Bmax
Minimum dose required to produce a specified response is determined in each member of a population
Quantal Dose-Response Curve
Formula for therapeutic index
TD 50 divided by ED50
Efficacy is measured through _____ dose response curves
Graded
Receptors that do not bind when the drug concentration is sufficient to produce maximal effect
Spare receptors
In the presence of an agonist, a partial agonist can act as _______
Antagonist
Effects of competitive antagonists can be overcome by
Adding more agonist
Competitive antagonists shift the dose response curve to the
Right
Non competitive antagonists causes a ____ shift to the dose response curve
Downward shift
This type of antagonist binds to q different receptor and produces an effect opposite to that produced by the drug it is antagonizing
Physiologic antagonists