Pharmacokinetics Flashcards
What does ADME stand for
Absorption
Distribution
Metabolism
Excretion
What is absorption
When drug goes into blood after administering
What is distribution
When drug gets taken around the body or to the site of action
What is metabolism
When drug is changed chemically into a more polar molecule to be excreted or eliminated
What is excretion
Drug is removed from body
What is routes of administration
Intravenous injection
Intramuscular injection
Subcutaneous injection
Epidural injection
Intrarticular injection
Intraperitoneal injection
Oral - drugs
What is a intravenous injection
Inject into vein
What is a intramuscular injection
Inject directly into muscle
What is a subcutaneous injection
Just under the skin
What is an epidural
Inject into spine
What is an interarticual injection
Into the joint
What is the interperitoneal injection
Inject into peritoneal space
What is oral administration
Drugs are given through the mouth in:
Tablet
Capsules
Powders
Solutions
Suspensions
What factors effect they way a drug is delivered
Is it available in a tablet or liquid form
Condition that is being treated
Chemical properties of the drug
Is the drug irritable to tissues - can the injected
How easy is it to administer to the animal
What do drugs contain
Infers
Lubricants
Disintergrants
Preservatives
Colours
Coatings
What are binders in drugs
Ensure tablets have the correct strength and hardness - allows drug to stay together in the bottle and mouth and disintergrate in stomach or intestine
What are lubricants in oral tablets
Make powder flow into the tablet press proprly e..g silica gel
What are disintegrants
Make tablet disintegrate in stomach or intestine
What are preservatives
Protect sensitive drugs against oxidation or bacterial damage
What are colours important for when it comes to tablets
Identify drug and dose
Why do we have coatings on drugs
Protect form environments dn make it easier to swallow
What does absorption depend on
Animal species
Age
Gender
Genetic factors
Metabolism
State of health/disease
What happens to oral tablets during disintegration
Tablet gets to stomach it has to disintegrate, if it doesnt it will only lose its outer cat - wont be as effective.
When tablet disintegrates the fragments spread throughout the stomach - they have a larger surface area
More surface area = faster distribution
What ais the rule of 5
No more than 5 hydrogen bond donors
No more thn 10 hydrogen bond acceptors
Molecular weight less than 500
Log p should be less than 5
What is bioavailability
How much drug enters blood
What is the bioavailability of drugs that are given orally
Less than 1
What is the bioavailability of drugs that are given intravenously - 100%
What is volume distribution
The theoretical volume that would be necessary to contain the total amount of an administered drug at the same concentration as is observed in the blood lasma
- measure of how slug is distributed around the body
How does the drug leave the blood
Capillaries - 1 cell thick - allows infusion from the molecules into surrounding tissues - only work for small molecule drugs
Capillaries have greatest surface area
What is tissue perfusion
Affects how rapidly drugs are distributed to different tissues
What happens to dru distibution in different vascularised tissues
Poorly vascualrised tissues = drugs slowly distributed
Well vascularised tissues - drugs rapidly distributed
What happens to drugs when area has different blood supplies
Good supply - distrubuted faster
Pooor supply - distrubuted slower
What does protein binding plasma do to distribution fo drugs
Protein binding affects distribution of drugs
Drugs bind to different proteins e.g. albumin
Can drugs bound to proteins go through capillaries
No hey cannot only drugs who are on their own can go through cappilarries
