Pharmacology

Question 1

What is pharmacokinetics?

Answer 1

The movement of drugs within the body
How the body affects the drug including absorption, distribution, metabolism and excretion

Question 2

What does pharmacokinetic absorption refer to?

Answer 2

The process of how the drug gets into the bloodstream
Speed of absorption determines onset of action

Question 3

What are 5 factors that affect absorption?

Answer 3

Route of administration
Formulation/properties (solubility, size, preparation),
Blood flow to administration site
Drug interactions
Ability of drug to cross biological barriers

Question 4

What route of administration is subject to first pass metabolism?

Answer 4

PO

Question 5

What route gives immediate and complete bioavailability?

Answer 5

IV

Question 6

What routes can give local +/- systemic effects?

Answer 6

TD
INH
PR
T (not really systemic)
IN
NEB

Question 7

What routes are considered rapid?

Answer 7

IV
INH
SL
IN
NEB

Question 8

What is bioavailability?

Answer 8

The amount of drug that reaches systemic circulation and is available to produce effect
Affected by absorption

Question 9

What is pharmacokinetic distribution?

Answer 9

How the drug spreads throughout the body and to the site of action once it has been absorbed into the bloodstream

Question 10

What are 6 factors that affect distribution?

Answer 10

Blood flow to area (more blood = more drug carried)
Tissue permeability (how well drug can cross barriers - lipophilic cross membranes better)
Protein binding (drugs bound to proteins are less distributable)
Blood brain barrier (only some drugs can cross)
Distribution to body compartments (may move to useless spaces e.g. extra cellular fluid)
Metabolism (may be converted to inactive metabolites in liver)

Question 11

What is pharmacokinetic metabolism?

Answer 11

Process of drug transformation/break down
Affects duration of action and excretion
Primarily takes place in liver (also sweat, bile, renal, lung) via cytochrome P450 enzymes

Question 12

What is a phase I metabolic reaction?

Answer 12

Drug is modified to make it more water soluble for easier excretion by kidney

Question 13

What is a phase II metabolic reaction?

Answer 13

Combines drug with a compound to make it more water soluble for easier excretion by kidney

Question 14

What is an enzyme induction/inhibition metabolic reaction?

Answer 14

Induction: drug increases activity of enzyme which leads to increased metabolism of other drugs

Inhibition: drug decreases activity of enzyme which leads to decreased metabolism of other drugs

Question 15

What are 4 outcomes of drug metabolism?

Answer 15

Inactivation: converts drug to inactive metabolite
Activation: converts drug to an active form
Toxic metabolite: may convert to a toxic metabolite
Pharmacogenetics: individual genes may cause altered activity

Question 16

What is pharmacokinetic excretion?

Answer 16

How the drug and metabolites are removed from the body
Primarily in the kidney (also liver, lung, gut and sweat)

Question 17

What are 4 factors that can affect renal excretion?

Answer 17

Impaired renal function
pH of urine
Urine flow rate
Protein bound drugs less likely to be filtered

Question 18

What are pharmacodynamics?

Answer 18

The effect that the drug has on the body and its mechanism of action

Question 19

What are the 4 main interactions that drugs have with receptors?

Answer 19

Agonist: activates the receptor
Antagonist: blocks the receptor from being activated
Partial agonist: binds weakly and partially activates (weak response)
Inverse agonist: binds to receptor and stabilises them in an inactive state producing the opposite affect of an agonist

Question 20

What is the difference between a side effect and an adverse effect?

Answer 20

Side effect is a more predictable result of a drug, may not result in harm

Adverse effect is an unpredictable result from a drug that causes harm

Question 21

What is specificity?

Answer 21

Extent to which a drug selects its intended receptor site

Question 22

What is affinity?

Answer 22

The strength of the bond between the drug and receptor site

Question 23

What is potency?

Answer 23

The relative quantity of drug required to produce the intended effect on the body

Question 24

What is efficacy?

Answer 24

The extent to which a drug produces the maximal effect

Question 25

What is therapeutic range?

Answer 25

Range of drug concentration where it is effective and safe
Above this concentration side effects and toxicity can occur

Question 26

What is the difference between first and second generation antihistamine?

Answer 26

First is non-selective and crosses BBB = sedative effect
E.g. diphenhydramine, chlorpheniramine

Second is selective to peripheral receptors only
E.g. cetirizine, loratadine

Question 27

What are the 4 classes of anticoagulants?

Answer 27

Vitamin K antagonist - warfarin
Factor Xa inhibitor (clotting factor) - rivaroxaban
Direct thrombin inhibitor (clotting factor) - dabigatran
Heparin + LMWH (increase anticoagulant antithrombin III)

Question 28

How do antibiotics work?

Answer 28

Penicillin and cephalosporins interfere with bacterial cell walls causing rupture
Macrolides (mycins) and tetracyclines bind to ribosomes interfering with protein synthesis
Fluoroquinolones (oxacins) inhibit enzymes essential to DNA replication and repair

Question 29

What is an SNRI drug?

Answer 29

Serotonin and norepinephrine reputable inhibitor
Venlafaxine

Question 30

What is buspirone used for?

Answer 30

Long term antianxiolytic
Acts on serotonin and dopamine

Question 31

What is the legislation around drugs in Australia?

Answer 31

Poisons and Medications Schedule
Need a license to hold/store/administer drugs
Individual license will state which drugs and preparations can be used by you
S4 and 8 drugs need to be secured and accounted for

Question 32

What are the seven drug rights?

Answer 32

Right patient
Right drug
Right dose
Right time
Right route
Right reason
Right documentation