Drug Interactions

Question 1

In drug interactions, the effectsof one drug are changedby the presence of:

Answer 1

Another drug
Herbal medicine
Food or drink
Environmental chemical agent

Question 2

MAOi’s+ TyramineRich foods (eg. Cheese)

Answer 2

Harmful

Hypertensive crisis

Question 3

Anti-hypertensives+ Diuretics

Answer 3

Beneficial

Increased antihypertensive effect

Question 4

Magnesium + Aluminum

Answer 4

Beneficial
Decreased diarrhea
Decreased constipation

Question 5

Types of Drug Interactions

Answer 5

1. Drug -food
2. Drug -laboratory test
3. Drug -drug
4. Drug -herb
5. Drug -patient
6. Drug -procedure
7. Drug -environment

Question 6

Factors affecting Drug-Food Interaction

Answer 6

1. Formulation characteristics
2. Type of food
3. Ingested relative time of food and drug intake

Question 7

Physiological effects of food

Answer 7

Reduce gastric irritation
Increase gastric emptying rate
Stimulate gastric secretion of digestive enzymes, acids and bile

Question 8

■Potent enzyme inhibitor
■Effect persists for 72 hours
■Calcium channel blockers, statins, Antidepressants

Answer 8

Grapefruit

Question 9

Absorption increased by food

Answer 9

Acarbose
Groseofulvin 
Itraconazole 
Metoprolol 
Theophylline

Question 10

False (+) glucose in urine (Benedict’s test)

Answer 10

Penicillin, Chloramphenicol, VitC., INH, Streptomycin

Question 11

False (-) Thyroid Function test

Answer 11

Chlordiazepoxide

Question 12

Change in urine color

Answer 12

Rifampin (red-orange),
VitB2 (intense yellow),
Chloroquine (brown)

Question 13

Phenomenon that occurs when the effects (pharmacodynamics) or pharmacokineticsof a drug are altered by the prior administration or co-administration of a second drug

Answer 13

Drug-drug interaction

Question 14

complex molecule that bind/ interact with an active molecule such as drug or hormone

Answer 14

Receptor

Question 15

Ability to bind with receptors

Answer 15

Affinity

Question 16

Drug + Receptor —> Drug-receptor complex —> Response

Answer 16

Intrinsic Activity/Efficacy

Question 17

Amount or concentration of drug to elicit pharmacologic response

Answer 17

Potency

Question 18

2 key players of drug-drug interactions

Answer 18

Object

Precipitant

Question 19

Drug induces a change in the patient’s response to a drug without altering the pharmacokinetics

Answer 19

Pharmacodynamic interactions

Question 20

Change in drug action without altered plasma concentration

Answer 20

Pharmacodynamic interactions

Question 21

Reaponse equal to combined individual responses

Answer 21

Addition

Question 22

Aspirin + warfarin

Answer 22

Addition

Question 23

Alcohol + CNS depressants

Answer 23

Addition

Question 24

Response GREATER than combined individual responses

Answer 24

Synergism

Question 25

Trimethoprim + Sulfamethoxazole (antimicrobials)

Answer 25

Synergism

Question 26

Sildenafil and Iloprost(vasodilators)

Answer 26

Synergism

Question 27

Flucytosineand Amphotericin B (fungal infections)

Answer 27

Synergism

Question 28

Amoxicillin + Clavulanic acid (Co-amoxiclav)

Answer 28

Potantiation

Question 29

4 types of antagonism

Answer 29

■Chemical ■Functional ■Competitive/ Reversible ■Noncompetitive/ Irreversible

Question 30

Agonist and antagonist will react through a chemical reaction and the antagonist will counter the effect of the agonist

Answer 30

Chemical antagonism

Question 31

2 Agonist drugs that act independently of each other but has opposite effects that cancels out each other’s effects

Answer 31

Functional antagonism

Question 32

■Antagonist combines with receptor but has no intrinsic activity ■DisplacementEffect

Answer 32

Competitive / Reversible antagonism

Question 33

Antagonist binds to an allosteric site causing conformational change on the receptor inhibiting binding and eventually reducing response

Answer 33

Non-conpetitive / Irreversible antagonism

Question 34

Primary factors of assessing drug interactions

Answer 34

Onset Severity Documentation

Question 35

Determines the urgency with which preventive measures should be instituted to avoid the consequences of the interaction

Answer 35

Onset

Question 36

Assessing risk vs. benefit of therapeutic alternatives

Answer 36

Severity

Question 37

•Bothersome or unnoticeable•Does not affect therapeutic outcome•Additional treatment not required

Answer 37

Minor severity

Question 38

•Deterioration in patient’s clinical status•Additional treatment, hospitalization, extended hospital stay

Answer 38

Moderate severity

Question 39

•Life-threatening or capable of causing permanent damage

Answer 39

Major severity

Question 40

Determines degree of confidence that an interaction can cause an altered clinical response

Answer 40

Documentation

Question 41

Proven to occur in well-controlled studies

Answer 41

Established

Question 42

Very likely but not proven clinically

Answer 42

Probable

Question 43

May occur; some good data; needs more study

Answer 43

Suspected

Question 44

Could occur; data very limited

Answer 44

Possible

Question 45

Doubtful; no good evidence of altered clinical effect

Answer 45

Unlikely