ADME 2 - Tavalin Flashcards
What are the advantages of IV drug administration? Disadvantages?
Patient compliance near perfect, rapid and complete delivery with high bioavailability, no first pass effect, flexible rate of administration, veins are relatively insensitive to drug irritation.
It is expense, requires trained personnel, once administered drug is in and can not be removed, toxicity can be a danger with rapid administration.
What are the advantages of subcutaneous drug administration? Disadvantages?
Advants: bypass first pass, absorption can be varied: rapid from aqueous solution or slow from repository or insoluble preps, can be given by patient.
Disadvant: can be painful, irritant drugs cause local tissue damage, not suitable for large volumes. Max of 2 mL injections.
What are the advantages of intramuscular drug administration? Disadvantages?
advantages: avoid first pass, rapid absorption by simple diffusion through capillary membranes
disadvant: trained personnel, site of injection will change how fast it is absorbed, genders absorb differently, pain and tissue damage, max volume of 4-5 mL
IWhat are the advantages of introarterial drug administration? Disadvantages?
Can be used for delivery to specific target organs.
Requires experts or specialists.
What are the advantages of intrathecal drug administration? Disadvantages?
Injection into subarachnoid space.
rapidly bypasses blood brain barrier and can be used for local spinal anesthesia for treatment of CNS infections.
What are the advantages of inhalation drug administration? Disadvantages?
Can have either local or systemic effects. Rapid absorption.
Drugs must be volatile or gaseous, most often form of drug abuse (smoking), allergic reactions are dangerous.
What are the advantages of topical drug administration? Disadvantages?
easy and good for long release.
Drug must be very lipid soluble.
What are the advantages of mucous membrane drug administration? Disadvantages?
rapid absorption, but can lead to systemic toxicity
What are the advantages of eye drug administration?
good for local eye effects
What factors affect rate of drug distribution?
cardiac output and regional blood flow, tissue volume and capillary permeability
Where does most of the blood flow to and perfuse? Why is this important for drug distribution?
Brain, kidney, liver, heart in that order.
This is where drug concentration will rise most rapidly
In what two regions is capillary permeability different from the norm?
Brain - capillaries have tight junctions (blood-brain barrier) that severely restrict what can pass
KIdney - permeability is greatly increased, resulting in more extensive distribution.
What is the most common plasma protein drugs bind to? What is another one?
Albumin - comprises 50% of plasma protein.
Globulins.
These interactions are usually nonspecific and reversible.
Why is drug binding to plasma protein clinically important?
if the binding changes, the biovailable concentration can change dramatically.
What are the four major drug reservoirs? Describe the mechanism of each.
stomach - traps basic drugs due to ionization
Albumin - limits availability of free drugs
Tissue - Liver, thyroid, and bone can accumulate drugs.
Fat - lipid soluble compounds readily partition into fat, where it is stored.
