SM41_DrugAbsorptionandDistribution

Question 1

When a drug is administered _______, its bioavailability is 100%

Answer 1

intravenously

Question 2

Bioavailability

Answer 2

The fraction of an administered dose of unchanged drug that reaches the systemic circulation

Question 3

Routes of drug administration

Answer 3

Oral, Rectal, intrathecal (spinal canal), inhalation, topical application - transdermal of mucosal, parenteral - includes intravenous, intramuscular, subcutaneous, intraperitoneal

Question 4

Factors affecting oral absorption of drugs

Answer 4

1. direct interaction / gastric time
2. First pass metabolism
3. Transport inhibition

Question 5

Forms of absorption prone to first pass metabolism

Answer 5

Oral, rectal

Question 6

Rapid distribution sites

Slow distribution sites

Answer 6

rapid: brain, heart, liver, kidneys (high blood flow)
slow: muscle, most viscera, skin, fat (slow blood flow)

Question 7

Structural composition of BBB and Blood-CSF barrier

Answer 7

BBB: continuous capillaries, tight junctions, surrounding astrocytes; efflux supporting transporters

Blood-CSF: Comprised of a layer of cuboidal epithelial cells of the choroid plexus with restrictive tight junctions.