Drug Interactions Flashcards Preview

Medicine Term One > Drug Interactions > Flashcards

Flashcards in Drug Interactions Deck (38):
1

What factors modify drug interactions

Drug - drug interactions.
Herbal - drug interactions.
Food - drug interactions.
Drink - drug interactions.
Pharmacogenetic interactions.

2

Define object drug
Define percipient drug

Drug whose activity is effected by such an interaction

Agent which percipitates such a reaction

3

What drugs are most likely to cause a drug interaction

Drugs with a low therapeutic margin

4

What are examples of herbs that can cause drug interactions

➢ Ginseng
➢ Green teas
➢ Melilot
➢ Tonka beans
➢ Woodruff

5

What are the characteristics of susceptible patients

number of medicaments
Advanced age
Young
the critically ill
patients undergoing complicated surgical procedures

6

What is 5 examples of patients with chronic diseases that can induce drug interactions

Liver
Renal
Diabetes
Epilepsy
asthma

7

What are further examples of things that can cause drug interactions

Multiple prescribing physicians
Self prescription
Prolonged length of stay (hospital infections)

8

What are examples of pharmodynamics interactions that can cause a drug interaction

Antagonistic Interactions
direct agonism
Indirect agonism
Additive or synergistic interactions

changes in drug transport
fluid and electrolyte disturbances

9

What is an example of an antagonist interaction

beta-blockers such as atenolol will block the actions of agonists e.g. bronchodilators such as salbutamol

10

What happens in a synergist drug interaction do

When two drugs with same pharmological effect acting on the same receptor

11

What is a phrarmodynamic interaction

the phrarmodynamic interactions of a drug are changed due to the presence of another drug

12

What are examples of indirect agonism that Induce CNS depression

Benzodiazepines
tricyclics
alcohol
Warfarin
NSAIDs (Indomethacin)
Atenolol
verapamil

13

What are NSAIDs indirect antagonists for

antihypertensive medication
treatment for heart failure

14

In pharmokinetic drug interactions it is possible for one drug to alter what four factors?

Absorption
Metabolism
Distribution
Elimination

15

What are the absorption interactions caused by drugs

Formation of insoluble complexes
Altered PH.
Altered bacterial flora..
Altered GIT motility.

16

What kind of antibiotics destroy normal gut flora

Broad spectrum

17

What is the possible outcomes of destroyed gut flora

Oral contraceptive
digoxin toxicity

18

When is delayed absorption important

Drug has short half life
want high plasma levels rapidly

19

What does tetracycline and erythromicin form a complex with

iron, calcium, magnesium

20

What drugs can increase the pH

H2 antagonists,
proton pump blockers
antacids

21

Drug binding in the GI tract is affected by

the degree of ionisation

22

What are examples of what Cholestyramine resin binds to in the GI tract

warfarin, digoxin

23

What is an example of a rate limiting step in absorption

Gastic emptying time

24

What are example of drugs that delay gastric emptying time

anticholinergics,
tricyclic anti-depressants,
opiates

25

When does protein displacement occur

when there is a reduction in the extent of plasma protein binding of a drug caused by the presence of another drug

26

The displacement of a drug from plasma proteins results in the increase of

Bioavailability of the displaced drug

27

When does drug interaction involving metabolism occur

when drug induces or inhibits the metabolism of another

28

Where does metabolism occur

In the liver via the cytochrome P450 system

29

What are examples of drug that inhibit metabolism

clarithromycin,
erythromycin,
cimetidine,
ketoconazole,
omeprazole,
Metronidazole
CCBs (diltiazem)
(claire ejects cool kids over the moon)

30

What is warfarin inhibited by

Metronidazole
Omeprazole
cimetidine,

31

What drugs induce metabolism

barbiturates,
carbamazepine,
phenytoin,
rifampacin
tobacco smoke

32

The effect of enzyme inducers are usually

delayed 2-3 weeks

33

What us enzyme induction dependant on

age,
disease,
genetics
concurrent drug therapy

34

What can Rifampacin and Phenytoin induce

warfarin

35

What can induce steroids

Phenytoin

36

What can effect the elimination of drugs

Changes in GFR or tubular secretion

37

What can inhibit excretion

Verapamil/diltiazem
digoxin

38

What increase tubular reabsorption

lithium