UNIT 3 – PHARMACODYNAMICS

Question 1

It is the study of the effect of drugs on the body

Answer 1

PHARMACODYNAMICS

Question 2

how avidly a drug binds its receptor or how the chemical forces that cause a substance to bind its receptor

Answer 2

DRUG AFFINITY

Question 3

refers to the drug’s ability to activate the receptor once it has bound
to it

Answer 3

DRUG EFFICACY

Question 4

facilitate receptor activation

Answer 4

Agonist

Question 5

prevent receptor activation

Answer 5

Antagonist

Question 6

the point at which increasing a drugs dosage no longer increases the desired therapeutic response

Answer 6

MAXIMAL EFFICACY

Question 7

The concentration of drug in plasma that above these, toxic effects are precipitated.

Answer 7

MAXIMUM EFFECTIVE CONCENTRATION

Question 8

refers to the amount of drug needed to elicit a specific physiologic response
or desired effect of a drug to produce a reaction. The maximal effect that a drug
produces irrespective of concentration or dose.

Answer 8

POTENCY

Question 9

Both Drug A and Drug B achieve the same maximum effect

Answer 9

they have equal efficacy

Question 10

has higher potency than Drug B

Answer 10

Drug A

Question 10

achieves this effect at a lower dose

Answer 10

drug A

Question 10

is more POTENT than Drug B

Answer 10

Drug A

Question 10

describes the relationship between the therapeutic dose of a drug (ED50) and the toxic dose of a drug (TD50)

Answer 10

Therapeutic Index

Question 10

the drug is moresafe to give

Answer 10

The higher the therapeutic index

Question 10

TI =

Answer 10

TD50/ED50

Example: TD50 is 500 mg and ED50 is 250 mg = 500 / 250 = 2

Question 10

need to be monitored closely for adverse effects.
Because the highest dose needed to produce a therapeutic effect is very close to the lethal or toxic dose.

Answer 10

Drug with lower therapeutic window

Question 11

therepeutic Index

low therapeutic index

Answer 11

• lithium
• neuroleptics
• some antibiotics
• digoxin
• immunosuppressives

Question 11

If a drug Therapeutic index is small

Answer 11

the drug is a narrow therapeutic index drug.

Question 11

If a drug Therapeutic Index is big

Answer 11

the drug is a wide therapeutic index drug

Question 11

therepeutic Index

High therapeutic index

Answer 11

• NSAIDs
• Sedative/hypnotics
• most antibiotics
• beta-blockers

Question 12

High therapeutic index

NSAIDs

Answer 12

• aspirin
• tylenol
• ibuprofen

Question 12

High therapeutic index

sedative/hypnotics

Answer 12

• benzodiazepines

Question 13

low therapeutic index

neuroleptics

Answer 13

• phenytoin
• phenobartibal

Question 14

low therapeutic index

some antibiotics

Answer 14

• gent/vanco/amikacin

Question 14

PARAMETERS OF DRUG ACTIONS

Answer 14

- ONSET - PEAK - DURATION OF ACTION

Question 15

# PARAMETERS OF DRUG ACTIONS Time from drug administration to first observable effect. The minimal effect of the drug is felt.

Answer 15

ONSET

Question 16

# PARAMETERS OF DRUG ACTIONS ONSET formula is

Answer 16

T0 – T1 ## Footnote Example: A drug is given at 8AM (T0) and give the minimum effect at 8:15 AM (T1), at 9AM (T2) the highest effectiveness of the drug was felt. At 10 AM (T3) the drug was no longer felt.

Question 17

# PARAMETERS OF DRUG ACTIONS PEAK formula is

Answer 17

T0 – T2 ## Footnote Example: A drug is given at 8AM (T0) and give the minimum effect at 8:15 AM (T1), at 9AM (T2) the highest effectiveness of the drug was felt. At 10 AM (T3) the drug was no longer felt.

Question 18

# PARAMETERS OF DRUG ACTIONS DURATION OF ACTION formula is

Answer 18

Formula is T1 – T3 ## Footnote Example: A drug is given at 8AM (T0) and give the minimum effect at 8:15 AM (T1), at 9AM (T2) the highest effectiveness of the drug was felt. At 10 AM (T3) the drug was no longer felt.

Question 19

# PARAMETERS OF DRUG ACTIONS Onset is 8am to 8:15 am =

Answer 19

15 minutes

Question 20

# PARAMETERS OF DRUG ACTIONS Peak is from 8am to 9am =

Answer 20

1 hour

Question 21

# PARAMETERS OF DRUG ACTIONS Duration of action is from 8:15 am to 10 am =

Answer 21

1 hour and 45 minutes

Question 22

DRUG RESPONSE

Answer 22

- Primary - Secondary ## Footnote Example: Diphenhydramine (Benadryl)

Question 23

# DRUG RESPONSE always desirable/physiologic effects

Answer 23

Primary

Question 24

# DRUG RESPONSE desirable or undesirable

Answer 24

Secondary

Question 25

# DRUG RESPONSE antihistamine; treat symptoms of allergy

Answer 25

Primary effect:

Question 26

# DRUG RESPONSE dizziness, sleepy, drowsiness

Answer 26

Secondary effect

Question 27

# DRUG-DRUG INTERACTION DRUG-DRUG INTERACTION

Answer 27

highest priority related to taking more than one medication.

Question 28

# DRUG-DRUG INTERACTION DRUG-DRUG INTERACTION

Answer 28

- Additive Effect - Synergistic - Potentiation - Antagonistic

Question 29

# DRUG-DRUG INTERACTION when two drugs given together have an effect equal to the sum of their respective effects.

Answer 29

Additive Effect

Question 30

# DRUG-DRUG INTERACTION drugs may increase each other’s effect to an amount that is greater than the sum of their individual effects. It increases the effectiveness of the drug.

Answer 30

Synergistic

Question 31

# DRUG-DRUG INTERACTION the interaction of one drug increased by the presence of a second drug.

Answer 31

Potentiation

Question 32

# DRUG-DRUG INTERACTION The combined effect of two drugs is less than the sum of their individual effects. It decreases the effectiveness of the drug.

Answer 32

Antagonistic

Question 33

Abnormal reactivity to the drug caused by a genetic difference between the patient and normal individual. For example one patient taking glutathione will result to healthy cells, whereas for patient with G6PD, glutathione will cause anemia.

Answer 33

IDIOSYNCRATIC REACTION

Question 34

The degree to which a drug can be poisonous and thus harmful to the human body. deleterious effects of drug over dosage or too much accumulation of drug on the blood stream.

Answer 34

DRUG TOXICITY