Excretion/elimination Flashcards
1
Q
Why is Renal excretion/elimination important
A
- most important route for many drugs
2
Q
3 stages of renal elimination
A
- glomerular filtration
- tubular secretion
- tubular reabsorption
3
Q
Effect pH has on ionizable drug excretion rate
A
- weakly acidic drugs: higher excretion in herbivores b/c urine more basic (7.0-8.0)
- weakly basic drug: higher excretion in carnivores b/c urine more acidic (5.5-7.0)
4
Q
Glomerular filtration
A
- non selective
- unidirectional
- all non protein bound drugs
5
Q
Tubular secretion
A
- carrier mediated process
- plasma protein binding doesn’t have effect
6
Q
Tubular reabsorption
A
- from tubular fluid -> capillaries
- occurs all along renal tubule
- increases 1/2 lives of drugs
- dependent on: urine flow rate, lipid solubility of non ionized drug moiety, and pH of urine
7
Q
Hepatic drug elimination
A
- glucuronide conjugates mainly excreted via bile
- glutathione conjugates ONLY excreted via bile
- drug must have highly polar funct. groups
- non polar drugs should be highly polar
8
Q
How is liver’s ability to metabolize and/or eliminate drugs affected by acute liver disease and chronic degenerative processes?
A
- reduced
- so must dose must be reduced to prevent accumulation and toxicosis
9
Q
Enterohepatic recycling; reaborption
A
- drug excreted into bile from systemic circulation & reabsorbed from SI back into blood
- prolongs 1/2 life of drug
- important mech. for enhanced activity of antiparasitic drugs (ivermectin)
10
Q
Excretion form for skin
A
Sweat
11
Q
Excretion form for lungs
A
Exhalation
12
Q
Excretion route for lacrimal gland
A
Tears
13
Q
Excretion route for mammary glands
A
Milk
14
Q
Excretion route for salivary glands
A
Saliva
