Medication Error and Drug Reactions Flashcards
(49 cards)
Additive drug drug interaction
1+1 = 2, two drugs taken and get same response as if taken by themselves
Potentiate drug drug interaction
a+b=B, increase the effect of 1 of the drugs (alcohol + cns drug= incapacitated)
Synergism drug drug interaction
1+1=5, response is greater then the normal of effect of the 2 drugs when taken together (tylenol +codeine)
Antagonism drug drug interaction
1+1 = 0, blocks the action of other drugs (morphine + naloxone)
Idiosyncratic drug drug interaction
1+1 = 437 or -5 or 65, uncommon response from genetic predisposition
-response is anything but what we expected
Inhibitory drug drug interaction
1+1= 0.5, 2 drugs taken together, action of 1 drug is decreased (phenylbarbitol + oral contraceptive)
Pharmacokinetic Interactions affecting absorption
- pH (acidic drugs absorb better in acidic enviro)
- increase or decrease peristalsis (laxative ^, opioid v)
- absorbent drugs- (cholestramine, metamucil)
Pharmacokinetic Interactions affecting distribution
-protein binding (warfarin, thyroxine, heparin)
Pharmacokinetic Interactions affecting metabolism
-CYP450
Pharmacokinetic Interactions affecting excretion
- alter the filtration, reabsorption or active secretion of drugs (cardiovascular system impact on excretion due to volume)
- p-glycoprotein (pumps drugs out of cells)
What route of medication gives most interactions?
IV
Where do interations between drugs occur
- same site
- different sites
What do we call the original drug of concern?
Substrate
What do we call the other drug/substance that inhibits metabolism of substrate? How does it work?
Inhibitor
- v metabolism > ^ drug available > toxicity
What do we call the other drug/substance that increases the metabolism of substrate How does it work?
Inducer
- ^ metabolism > v drug available > sub therapeutic response
Top 3 drugs causing ER visit for drug/drug interaction
digoxin, coumadin, insulin
3 general drug/food interaction scenarios
- v rate of absorption
- ^ rate of absorption
- GI Distress
What happens if food decreases the rate of absorption?
delay onset of drug
delay extent of absorption –> v intensity of peak effect
Mao Inhibitors can’t be taken with what kind of food? examples of these foods?
Tyramine rich
-chocolate, avo, beer, aged cheese, pepperoni, salmi, hot dog, fava bean
What happens if you take MAO inhibitors with Tyramine rich food?
Hypertensive crisis
Grapefruit/juice effects what metabolic pathway?
CYP450
What kinds of drugs can’t be taken with grapefruit juice?
- calcium channel blocker (HTN)
- statin drugs (cholesterol)
- transplant drugs
- SSRI
- versed (anesthesia)
What defines an empty stomach?
1 hr before meal or 2 hr after meal
What do you do if patient is continuous tube feed and needs med on empty stomach?
stop tube feed, give med after 2 hours, restart
