Pharmacokinetics Flashcards
What is the ADME concept?
Absorption; Distribution; Metabolism; Excretion
Relates to Absorption..
- Oral and nonoral absorption
- First pass concept
- Bioavailability/ Bioequivalence w/ generic drugs
Relates to Distribution…
- definition and relation to body water
- application - loading dose
Relates to metabolism..
- Phase 1 vs Phase 2
- active metabolites
- Clearance vs. rate of elimination and maintenance dose
- Pharmacogenomics
Relates to Excretion…
-Renal clearance and factors effecting
Explain pharmacokinetics..
(What happens to the drug)
- dose administered
- (absorption)
- Drug concentration in systemic circulation
- (Distribution)
- Drug in tissues of distribution
- (Elimination)
- Drug metabolized or excreted
Main routes of drug administration:
- oral/rectal
- percutaneous
- Intravenous
- Intramuscular
- Intrathecal
- Inhalation
Main routes of elimination:
- urine
- feces
- milk, sweat
- expired air
Route of oral/rectal:
Gut –> portal system –> liver–> metabolites –> bile and back to the gut or kidneys and through urine
- drugs enter the system through the liver/gut/kidneysplasma
- excreted through the feces
- First pass metabolism of drugs goes through here
- Concentration of drugs will be different from ingestion to the site of action.
Route of percutaneous:
On the skin and absorbs into the plasma.
Route of Intravenous:
Straight into the plasma.
Route of Intramuscular:
Into the muscle and to the plasma.
Route of Intrathecal:
CSF Brain< –> Plasma
Route of Inhalation:
Lungs plasma
Other absorption areas to be aware of:
- Fetus Placenta plasma
- Breast/sweat glands plasma
Drug through the stomach..
Disintegration –> Drug in small particles –> Dissolution –> Drug in solution
Where is the site of maximum absorption?
Small intestines
Where must the drugs absorb to get to the liver? What is so significant about this site?
Portal vein into the liver. This is where First-pass metabolism occurs.
Gastric Emptying Rate Factors:
- volume of meal
- meal composition
- viscosity
- osmotic pressure
- position
- drugs
What’s important about volume of meal?
Putting a lot of food in initially empties the gut but is followed by decreases emptying. (Liquids empty faster)