Intro-ADR-Part-I

Question 1

Drug Interaction

Definition

Answer 1

Occurs when the effects of one drug are modified by the prior and/or concurrent administration of another pharmacologically active substance.

Question 2

There are 2 types of DDI outcomes. These two terms are used for when there is an exaggeration of expected pharm effects

Answer 2

additive, synergistic

Question 3

There are 2 types of DDI outcomes. These two terms are used for when there is an attenuation/loss of expected pharm effects

Answer 3

antagonistic, silent

Question 4

The [object/precipitant] drug is the one that is affected by the interaction

Answer 4

Object Drug

Question 5

The [object/precipitant] drug is the one that causes the interaction

Answer 5

Precipitant Drug

Question 6

[PK/PD] DDIs result in a change in concentration-time in circulation/effector tissue/organ

Answer 6

PK

Question 7

[PK/PD] DDIs lead to a different pharmacologic response and drug/metabolite concentration

Answer 7

PD

Question 8

DDIs represent about __% of med errors in the in-patient setting

Answer 8

3

Question 9

While DDIs only make up 3% of med errors, we study them because they are largely ___________

Answer 9

Preventable

associated morbidity and mortality are often serious

Question 10

Overall, POTENTIAL to PROBABLE DDIs can range from _____ to _____%

Answer 10

1 to 20

Question 11

Variance in DDI range depend on:

1) C
2) P
3) U
4) D

Answer 11

1) Clinical & practice setting
2) Patient population
3) underlying disease or disorder
4) Drug distribution, utilization, and reimbursement policy (formulary)

Question 12

Clinical SIGNIFICANT DDI is estimated at ___ to ___/1000 PT, often with______

Answer 12

1 to 10

Serious adverse outcomes

Question 13

All of the following characteristics of an OBJECT DRUG affect the outcome of a DDI EXCEPT?
A. Elimination pathway of the object drug
B. First-pass metabolism of object drug
C. Therapeutic index of object drug
D. History of DDI involving the object drug

Answer 13

D is incorrect
Other factors influencing the interaction include: 
Disease states (CHF, CKD)
Genetics (transporters) 
Basal concentration of the drug

Question 14

All of the following characteristics of a PRECIPITATING DRUG affect the outcome of a DDI EXCEPT?
A. Dose/Concentration of Precipitant drug
B. Therapeutic index of precipitant drug
C. Time of administration related to object drug
D. Transporter activity of object drug

Answer 14

B is incorrect
REMEBER!
A precipitant drug is a drug that CAUSES AN INTERACTION!

Question 15

T/F:

Lack of suspicion/anticipation of a DDI is the most important factor increasing the risk of an adverse drug interaction

Answer 15

TRUE

Question 16

What is the most common mistake made when using published DDI studies to assess DDIs?

Answer 16

Assuming the mean values of these studies will apply to the patient you are considering.

Question 17

T/F:

Major Contraindication alerts from software should always be followed?

Answer 17

FALSE
50% of alerts are not contraindicated in the drugs labeling.
Many can still be administered under correct monitoring

Question 18

What is the likelihood of a CYP450-medicated drug interaction in an elderly patient on 6 different medications? 
A. 34%
B. 42%
C. 50%
D. 81%

Answer 18

C. 50%

The likelihood of a CYP-450 interaction in a patient taking 10-14 drugs is 81%

Question 19

What are the 7 potential pitfalls of DDI literature?

Answer 19

1. Extrapolation of an interaction from one member of a class to include the entire class
2. Extrapolation of an interaction from normal subjects to patients
3. Dose-Dependency of interactions
4. Time course of interaction
5. Assessment of case reports
6. Sequence of drug administration
7. Mean response vs. Individual responses

Question 20

What are 3 potential pitfalls to experiments that evaluate DDIs?

Answer 20

1. Measurement interaction taken too early or too soon
2. Titration of the object drug in presence of precipitant drug
3. Comparing mean vs individual response