Pharmaco stuff

Question 1

What are the 5 factors affecting drug absorption?

Answer 1

Chemical/ physical nature
Ex. Osmotic pills, slow-release pills
Route of administration
Blood flow
Dose
Drug solubility

Question 2

What is bioavailability?

Answer 2

Bioavailability: proportion of a drug that reaches the systemic circulation/ plasma.
IV: 100%
All other: <100%

Question 3

What are the 5 factors affecting drug distribution?

Answer 3

Blood flow
Lipid solubility
Diffusion Barriers
Tissue binding
Plasma protein binding

Question 4

Explain what is plasma-protein binding?

Answer 4

We have protein carriers in the blood that can bind the drug and transport it.
Ex. Albumin.
Bound drugs → NO biological effect
They also cannot be metabolised or excreted.
Free drugs → HAVE biological effect.
Plasma binding → affect drug half-life and efficacy.

Question 5

What are the 2 phases of hepatic metabolism?

Answer 5

aim is to decrease lipid solubility for renal excretion.
Phase 1 → cytochrome p450 (catabolic)
Phase 2 → conjugation of small hydrophilic substances (anabolic)

Question 6

Why is enterohepatic re-circulation important?

Answer 6

EHC plays a detrimental role as the compounds/drugs are allowed to recycle

Question 7

What are the 3 types of hormones?

Answer 7

Peptide, Steroid, Amine