Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

POD > Drug-Drug Interactions > Flashcards

Drug-Drug Interactions Flashcards

1
Q

Drug interaction

A

the modification of a drugs effect by prior or concomitant administration of another drug, herb, foodstuff or drink.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What type of drug interactions are there?

A
  • food
  • drink
  • pharmacogenetic
  • herbal
  • drug
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Object drug

A

the drug whose activity is effected by and interaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Precipitant

A

the agent which precipitates such an interaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What do drugs involved in serious interactions have in common?

A
  • they are all potent with a narrow therapeutic index

- this means that a small change in blood levels can induce profound toxicity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Who is susceptible to drug-drug interactions?

A
  • multiple medications
  • elderly
  • young
  • critically ill
  • surgical patients
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What conditions can increase the likelihood of having a drug-drug interaction?

A
  • liver disease
  • renal impairment
  • diabetes mellitus
  • epilepsy
  • asthma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the 3 mechanism of drug-drug interactions?

A
  • Pharmaceutical
  • Pharmacokinetic (absorption, distribution, metabolism, elimination)
  • Pharmacodynamic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What kind of pharmacodynamics interactions can take place?

A
  • antagonistic interactions
  • additive or synergistic interactions
  • interactions de to changes in drug transport
  • interactions due to fluid and electrolyte disturbances
  • indirect pharmacodynamics interactions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the mechanisms of absorption reactions?

A
  • formation of insoluble complexes
  • altered pH
  • altered bacterial flora
  • altered GIT motility
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What do most interactions of drugs in the GIT result in?

A

changes in absorption rather than the extent of absorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

When is delayed absorption important?

A

when a drug has a short half life or when we want high plasma levels rapidly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What drugs bind together in the GIT??

A
  • tetracycline and erythromycin complex with Fe, Ca and Mg

- cholestyramine resin can bind to warfarin and digoxin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How does pH affect absorption?

A
  • absorption is affected by the degree of ionisation which is dependent on pH
  • H2 antagonists, proton pum blockers and antacids reduce H+ and so increase the pH
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What may lead to the failure of the OCP or digoxin toxicity?

A

-broad spectrum antibiotics destroy normal gut flora

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Where are most oral medicines absorbed?

A

small intestine

17
Q

What is the rate limiting step in drug absorption?

A

gastric emptying

18
Q

What drugs increase/decrease gastric emptying?

A
  • decrease: anticholinergics, tricyclic anti-depressants, opiates
  • increase (domperidone, metoclopramide)
19
Q

When does protein-binding displacement occur?

A

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

20
Q

What is the result of displacement of a drug from plasma protein?

A

increased bioavailability as only the unbound drug is pharmacologically active

21
Q

What are the 2 most important proteins in protein binding?

A
  • albumin

- a1-glycoprotein

22
Q

How are some patients protected by interactions?

A

increased metabolism and excretion

23
Q

When do drug interactions involving metabolism occur?

A

when one drug induces or inhibits the metabolism of another

24
Q

Where does metabolism commonly occur?

A

in the liver via the cytochrome P450 system

25
Q

What drugs inhibit the cytochrome system?

A
  • clarithromycin
  • erythromycin
  • CCBs
  • omeprazole
  • ketoconazole
26
Q

What are potent induced of cytochrome P450?

A
  • barbiturates
  • carbamazepine
  • phenytoin
  • rifampicin
  • tobacco
27
Q

How can the metabolism of ciclosporin be increased?

A
  • rifampicin induces CYP3A4

- St John’s Wort induces CYP3A4

28
Q

How are most drugs excreted?

A

in urine or bile

29
Q

How are digoxin and lithium eliminated?

A

by the kidney

30
Q

What drugs inhibit excretion?

A

verapamil/diltiazem and digoxin

31
Q

What drugs increase tubular reabsorption?

A

loop diuretics and lithium

32
Q

When do pharmacodynamics interactions occur?

A

when the pharmacodynamics actions of a drug either acting directly on the same receptor or indirectly on different receptors

33
Q

How can pharmacodynamics interactions be described?

A
  • direct
  • indirect
  • antagonistic
  • synergistic/agonistic
34
Q

Pharmacodynamic interactions: direct antagonism

A

beta blockers such as atenolol will block the actions of agonist e.g bronchodilators (salbutamol)

35
Q

Pharmacodynamic interactions: synergistic interaction

A

when two drugs with the sam epharmacological effect acting on the same receptor are given concurrently

36
Q

Pharmacodynamic interactions: indirect agonism

A

-CNS depression
benzodiazepines and tricyclics or alcohol
-warfarin and NSAIDs
-atenolol and verapamil

37
Q

Pharmacodynamic interactions:

A
  • NSAIDs and antihypertensive medication

- NSAIDs and treatment for heart failure

38
Q

How to deal with an interaction

A

If the altering dose timing or no alternative doesn’t solve the issue adjust drug dosage +/- monitor drug level (TDM) and physiological functions

POD (54 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions