Module 4 Pharmacokinetics Feb 9

Question 1

What organs eliminate - 2

Answer 1

Kidneys

Liver

Question 2

Ways drugs cross cell membranes - 3

Answer 2

Pores and channels
Transport systems - incl. P-glycoprotein reverse transport
Direct penetration - lipid soluble

Question 3

Ion trapping

Answer 3

Weak acid in acid, moves across to basic side, ionizes, trapped
Reverse for weak base

Question 4

Types of routes of administration - 2/8

Answer 4

Enteral - Oral, Rectal, Sublingual

Parenteral - IV, IM, Subcutaneous, Inhalation, Transdermal patches

Question 5

Affects Absorption - 10

Answer 5

Formulation, Drug molecule characteristics, % uncharged form,
+/- food, Blood flow, Concentration gradient, Surface area,
Contact time, Pgp reverse transporter, First Pass effect

Question 6

Factors affecting Distribution - 5

Answer 6

Drug characteristics, Blood flow, Capillary permeability,

Plasma protein binding, Patient and disease factors

Question 7

Special Distribution issues - 3

Answer 7

Blood brain barrier,
Placenta,
Breast milk

Question 8

Plasma Protein binding - 4

Answer 8

Mostly albumin
Reversible or not
Reversible may be displaced by another drug, interaction
Nutritional status and plasma protein levels affect this

Question 9

Metabolism - where, mechanisms, specific enzyme family

Answer 9

Mostly in liver
Enzymes, make more polar for excretion
CYP450 Enzyme family (P450 CYP3A4)

Question 10

Metabolism - Substrate, Metabolite, Pro-drug

Answer 10

Substrate - drug that enzyme acts on
Metabolite - product of biotransformation
Pro-drug - inactive until metabolized, then active

Question 11

Induction/Inhibition

Answer 11

Metabolic enzymes can be inducted or inhibited

Induction means make more, when metabolizes and removes drug, so induction drug make other drug work less or not at all

Question 12

Factors affecting Metabolism - 7

Answer 12

Age, Sex, Genetic variants, Diet (grapefruit juice), Smoking,
Other drugs, Liver disease

Question 13

Elimination patterns - 2

Answer 13

First order elimination - half life time

Zero order elimination - constant, no half life, but unpredictable

Question 14

Steady State occurs when

Answer 14

4-5 half lives

Question 15

PK Effects of body on drug 3/4

Answer 15

Absorption-Site of admin to systemic circulation
Distribution-Systemic circulation to tissues
Elimination-Removal from body
- Metabolism
- Excretion