Excretion, Pharmacodynamics, Interactions

Question 1

Where do drugs, metabolites and conjugates go?

Answer 1

Low molecular weight polar drugs are exerted in urine
High molecular weight lypophylic metabolites excreted via faeces

Question 2

How does excretion through the kidney work?

Answer 2

Blood goes into kidney and Ito the inter lobular arteries
Goes to glomerulus
Drugs and metabolites diffuse from flood into the developing urine into to the glomerulus capsule
Urine passes through loop of hence
Urine goes down convulated tubules into the renal pelvis
Urine goes don uterus into bladder where it is excreted out the vagina/penis

Question 3

How does tubular secretion work

Answer 3

Kidney tubular cell secretemetabolites from the capillaries surrounding the tubule into the glomerular filtrate
Becomes urine as it leaves kidneys through active transport
More rapid process

Question 4

What happens if an animal has a disease tat affects parts of the glomerulus

Answer 4

Toxic levels of the drug can cumulate epically if the drg is given a couple of times a day as it cannot be metabolised

Question 5

How are drugs excreted in bite

Answer 5

Passive diffusion occurs from blood to the hepatic aftery into the liver
High molecular weight drugs and metabolites go into the duct from the liver into the common bile duct where it mixes with bile in the gall bladder
The drug/bile mixture goes into the duodenum via the common bile duct
It gets recycled and goes back to the liver but most goes down the duodenum
Ileum
Colon
Rectum
Anus and is excreted as faeces

Question 6

What is the concentration response curve

Answer 6

Take 50% of curve which gives you 50% of the bilgica response

Question 7

Issues with the concentration response curve?

Answer 7

Any errors.variability with the data will cause variability in the 50% biological response

Question 8

What does the therapeutic window show

Answer 8

Pink area = toxicity/adverse response
Yellow - sub therapeutic concentration
Green = desired response
It shows the duration of action - time it takes to get the desired response

Question 9

What happens if there are drug-drug interactions

Answer 9

It can result in antagonism if drugs are going for the same enzyme
Pharmacokinetic interactions occur when one drug changes the dme of the other - usually metabolism but sometimes absorption and elimination.
It will cause one drug to be less effective