Oral Absorption - PreLecture Flashcards
What is route of an orally absorbed drug?
- Absorbed from GIT through gut wall
- Portal vein
- Liver
- Systemic circulation and site of action
What is the difference between FA and F?
FA: faction of drug absorbed from gut wall to portal vein
F: Bioavailability where a drug is bioactive at the site of action
What order is the drug transfer from GIT to body?
zero or first
What is the order of drug elimination of oral absorption?
first
Describe the compartmentalization of oral absorption?
What is the equation for 0 order oral absorption?
What is the equation for 1st order oral absorption?
What are the phases of drug absorption?
- Absoprtion
- Peak drug concetration
- Post absorption phase
- Elimination phase
When does elimination occur?
As soon as absorption starts
What rate is great absorption or elimination prior to Cmax?
Absorption
What occurs at peak drug concentration?
- Tmax
- Drug absorption is equal to elimination
When does post-absotion phase occur?
Immediately after Cmax
What rate is great absorption or elimination post Cmax?
elimination
What occurs during the elimination phase?
- Absorption depletes and rate approaches zero
- Elimination rate is great
- Point plasma concentration declines and behaves like IV bolus
If ka increases (while k is unchanged) what are the effects on Tmax, Cmax and AUC?
a. Tmax decreases
b. Cmax increases
c. AUC is unchanged