Lecture 3 Absorption Flashcards
1
Q
Pore transport
A
- urea, water, and sugars movement through pores
- the model of drug permeation through aqueous pores is used to explain renal excretion of drugs and the uptake of drugs into the liver
- a transport protein may form an open channel across the lipid membrane of the cell
- Small molecules including drugs move through the channel by diffusion more rapidly than at other parts of the membrane
2
Q
Ion-Pair Formation
A
- Strong ionic hydrophillic ( water soluble) drugs cannot pass through the membrane
- Pair with oppositely charged molecule to neutralize the charge and diffuse
3
Q
Methods of transporting materials into cell
A
- Pinocytosis
- Phagocytosis
- Pore transport
- Ion-pair formation
4
Q
Pgp Inducers
A
- St. John’s wort
- Rifampin
- Ritonavir
- Retinoic Acid
- Clotrimazole
- Dexamethasone
- Morphine
- Phenothiaine
- Saquinavir
5
Q
PgP inhibitors
A
- Atorvastatin
- Carvedilol
- Erythromycin
- Itraconazole
- Ketoconazole
- Meperidine
- Methadone
- Progesterone
- Ritonavir
- Saquinavir
- Tamoxifen
- Verapamil
6
Q
Absoprtion from the lymphatic system
A
- Bypass liver
- avoid first pass metabolism
- Drain into the vena cava rather than hepatic portal
7
Q
Eating fatty meals
A
- decrease absoprtion of some antibiotics and hydrophillic drugs
- However, for lipid soluble drugs such as griseofulvin, they are better absorped with food containing high fat concent because it stimulate flow of bile, and increases solubility via micelle formation
8
Q
Facilicated diffusion
A
- Does not require energy input
- Moves from high to low concentration
- Saturable
- Requires carrier
- Facilitated diffusion therefore allows polar and charged molecules, such as carbohydrates, amino acids, nucleosides, and ions, to cross the plasma membrane.
- Two classes of proteins that mediate facilitated diffusion are generally distinguished: carrier proteins and channel proteins.
