Drug Interactions: Part 1

Question 1

Drug interaction

Answer 1

An altered or modified action or effect of a drug as a result of interaction with one or multiple drugs

Question 2

Is drug interaction the same as adverse drug reaction and drug incompatibility?

Answer 2

NO

Question 3

Drug to drug interactions can occur…

Answer 3

Anytime when a client takes two or more drugs

Question 4

Intended interaction example

Answer 4

Hypertension therapy

Diuretics + Beta blockers

Question 5

Unintended interaction example

Answer 5

CNS depression
Narcotics + Benzodiazepines
Narcotics + alcohol

Question 6

What things could increase gastric emptying time and alter absorption?

Answer 6

Laxatives, metoclopramide (Reglan)

Question 7

What things could cause decreased gastric emptying time and alter absorption?

Answer 7

Opioids, anticholinergic drugs

Question 8

Change in pH of the stomach could alter absorption by…

Answer 8

Antacids ( many drugs rely on acidity)

Question 9

Examples of drug complexes forming to alter absorption

Answer 9

Specific cholesterol-binding drugs (bind to cholesterol and carry it through GI but also bind any other drug)

Question 10

Altered distribution of drugs

Answer 10

Drug concentration in the blood

Protein-binding of blood

Question 11

Protein- binding of blood

Answer 11

Compete for binding sites on protein - can lead to drug toxicity

Question 12

Altered metabolism of a drug can be caused by..

Answer 12

P450 Enzymes
Enzyme induction
Enzyme inhibition

Question 13

Dilantin (Phenytoin)…

Answer 13

Induces P450 enzymes

Question 14

Tagamet is an OTC drug that…

Answer 14

Inhibits P450 enzymes, can lead to toxicity

Question 15

Altered renal excretion could be caused by.. (3)

Answer 15

Decreased cardiac output
Competition for excretion
Change in urine pH

Question 16

Additive drug effect

Answer 16

1+1=2
Sum of the effect of of both drugs
Work together to have the same effect

Question 17

Synergistic drug effect (Potentiation)

Answer 17

1+1=3

Clinical effect is much greater than the sum of both (one makes the other much better)

Question 18

Example of synergism

Answer 18

Morphine leads to nausea, Phenergan is anti-nausea but also has CNS depression so will help with pain (loopy)

Question 19

Antagonistic drug effect

Answer 19

1+1=0
Morphine + naloxone (Narcan)
(Naloxone is the antidote)

Question 20

What types of foods can delay onset of effects of a drug / decrease absorption?

Answer 20

Dairy products (antibiotics) 
High-fiber foods

Question 21

What drug has increased absorption with food?

Answer 21

Lopressor (beta blocker)

Question 22

Grapefruit juice effect

Answer 22

Inhibits metabolism by the P450 enzymes (CYP3A4), leads to increased drug levels in blood stream

Question 23

Coumadin and Vitamin K

Answer 23

Vitamin K is essentially an antidote for Coumadin

Question 24

Timing of drug administration with meals (options)

Answer 24

With food

On an empty stomach

Question 25

Herbal therapies are defined as ______ by the FDA

Answer 25

Dietary supplements

Question 26

Can supplements claim to prevent, treat or cure disease?

Answer 26

No

Question 27

Without full FDA regulation, ________ remains a concern with herbal supplements

Answer 27

Standardization

Question 28

St. john’s wort

Answer 28

Anti-depressant and anti-anxiety

Include P450 enzymes = loss of therapeutic

Question 29

Ma huang (ephedra)

Answer 29

Used for energy or weight loss

Intensify cardiac / CNS stimulants, many women dropped dead

Question 30

Ginkgo biloba

Answer 30

Suppresses platelet aggregation

Question 31

What is drug- induced photosensitivity?

Answer 31

Skin reaction caused by taking a medication that increases sensitivity to sun while taking that medication

Question 32

Prevention of drug-induced photosensitivity

Answer 32

Sunscreen with SPF 15

Question 33

Adverse drug reactions

Answer 33

Any undesireable drug effect

Question 34

Side effect / Adverse effect

Answer 34

Nearly unavoidable secondary drug effect produced at therapeutic doses

Question 35

Toxicity

Answer 35

Adverse drug reaction caused by excessive dosing

Question 36

Allergic reaction

Answer 36

Immune response to a medication (mild to anaphylaxis)

Question 37

Idiosyncratic effect

Answer 37

Uncommon drug response resulting from a genetic disposition

Question 38

Teratogenic

Answer 38

Drug-induced birth defects (many anti-seizure medications)

Question 39

Carcinogenic

Answer 39

Ability of medications to cause cancer