Pharmacodynamics

Question 1

Therapeutic index

Answer 1

• a measure of the safety of a drug.
• the ratio of the lethal dose in 50% of the patients and the minimum dose at which therapeutic effect occurs
• at what amount of med does it become toxic or lethal and at what does is it therapeutically effective
• need to assess narrow index more safely.

Question 2

A higher dose would create…

Answer 2

a greater effect

Question 3

If a dose is doubled the response would have…

Answer 3

twice the effect

Question 4

Symptom unique to Digoxin toxicity

Answer 4

Halos around objects

Question 5

Potency

Answer 5

• the relative amount of drug required to produce a desired response.
• a drug that is more potent will produce a therapeutic effect at a lower dose.

Question 6

Efficacy

Answer 6

a measure of the magnitude of the maximal response in a patient that can be produced from a particular drug
- more important than potency - at what point will we see a therapeutic effect

Question 7

Drug actions (the mechanism of drug actions in living tissues)

Answer 7

1. receptor interactions
2. enzyme interactions
3. nonspecific interactions

Question 8

Drug effect (the physiologic reaction of the body to the drug)

Answer 8

• Drug potency and therapeutic index

Question 9

Receptor Interactions

Answer 9

a molecule to which a medication binds to initiate its effect. can be selective or nonselective

Question 10

Selective receptor interaction

Answer 10

binds with only one type of receptor

Question 11

Nonselective receptor interaction

Answer 11

binds with several types of receptors

Question 12

Agonist

Answer 12

a drug can produce a response that mimics the effect of the endogenous regulatory molecule

Question 13

Partial agonist

Answer 13

a medication that produces a weaker or less effective response than an agonist

Question 14

Antagonist

Can be:

Answer 14

Block a receptor

• competitive (compete with agonist for receptor sites - will lose if there is more agonist)
• non competitive (binds with receptor sites and blocks the effects of the agonist no matter the dose, always wins) - functional (does not bind to receptor, works against agonists to slow drug absorption of speed up metabolism or excretion)

Question 15

Enzyme Interactions

Answer 15

For a drug to alter enzyme interactions, it must inhibit a specific enzyme by fooling it
- the enzyme binds to the drug instead of to the normal target cell

Question 16

ACE (angiotensin converting enzyme)

Answer 16

normally causes the production of angiotensin II (vasoconstriction)

• ACE inhibitors fool ACE into binding to them instead.
• less angiotensin II is made and therapeutic response is that BP is lowered.

Question 17

Nonspecific Interactions

Answer 17

• Doesn’t directly involve receptors or enzymes

- instead, cell membranes or metabolic processes are the biochemical target

Question 18

Once the drug is at the site of action it can…

Answer 18

modify the rate (increase or decrease) at which the cells or tissues function

Question 19

Pharmacotherapeutics

Answer 19

use of drugs in practice
seeking therapeutic responses
- the use of drugs and the clinical indications for drugs to prevent and treat diseases

Question 20

Acute therapy

Answer 20

ie, in ICU or trauma rooms - high risk meds in controlled environments

Question 21

Maintenance therapy

Answer 21

ie, chronic disease management. HTN, DM 2 meds

Question 22

Supplemental therapy

Answer 22

TPN, insulin

Question 23

Palliative therapy

Answer 23

care vs cure; narcotics, anti-anxieties

Question 24

Supportive therapy

Answer 24

supports physiologic needs, ie. fluids & electrolytes, blood products, oxygen

Question 25

Prophylactic thearpy

Answer 25

ABX for asplenic pts

Question 26

Empiric therapy

Answer 26

based on precedence rather than research. ie, use of acetaminophen in a fever of unknown origin

Question 27

Nurses role in preventing and managing drug effects

Answer 27

• obtain medical history
• prevent medication errors from occurring
• thoroughly assess the client and all diagnostic data
• monitor carefully
• know the drugs

Question 28

Know the Drugs - The effectiveness of drug therapy must be evaluated

Answer 28

• one must be familiar with the drugs:
• intended therapeutic action (beneficial)
• unintended but potential side effects (predictable, adverse reactions)

Question 29

Monitoring Pharmacotherapy carefully

Answer 29

• therapeutic index
• drug concentration
• patients condition
• tolerance and dependence
• interactions
• side effects/adverse drug effects (potential lethal and most common)

Question 30

Adverse Drug Reaction

Answer 30

an adverse outcome of drug therapy in which a patient is harmed in some way

Question 31

Pharmacologic Reations

Answer 31

In works too well. antihypertensive leads to extreme hypotension

Question 32

Idiosyncratic reactions

Answer 32

particular to the patient, but not a true allergy or a pharmacologic reaction. Eg, pt develops migraine with Percocet

Question 33

Allergic reaction

Answer 33

allergies - patient’s immune system decides to treat a drug as a dangerous character and overreacts

Question 34

Teratogens

Answer 34

anything that can damage the fetus. alcohol and cocaine. cause birth defects

Question 35

Dose dependent effect

Answer 35

• some adverse drug reactions are classified as side effects:
  expected, well-known reactions that result in little or no change in patient management
  occur with predictable frequency
  the effects intensity and occurrence are frequently related to the size of the dose.

Question 36

Drug toxicity

Answer 36

• nephrotoxicity
• neurotoxicity - especially sensitive to small amounts of toxic substances.
• hepatotoxicity
• Dermatological
• Bone marrow
• Cardiotoxicity
• Skeletal Muscle and Tendon

Question 37

Additive Effect

Answer 37

when two drugs are given together and they add to the others effectiveness

Question 38

Synergistic effect

Answer 38

multiplication of magnitude. equals more than they would on their own.

Question 39

Antagonistic effect

Answer 39

two drugs are given and one can cancel out the effects of the other. or one may increase the excretion

Question 40

Incompatability

Answer 40

• when parenteral drugs are mixed together and form a precipitate that can be lethal