Medication Error and Drug Reactions Flashcards
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
Any noxious, unintended, undesired effect that occurs at normal drug doses
ADR- adverse drug reaction
Nealy unavoidable secondary drug effect produced at therapeutic doses
side effect
Who is at highest risk for ADR?
older adults- polypharmacy
What is definition of toxicity?
excessive dosing
What population is more sensitive to CNS drugs?
Asian
What is leading cause of acute liver failure?
drugs , >50 can cause it
What tests monitor liver fxn? Sxs?
AST, ALT
-monitor s/s of hepatitis (jaundice, anorexia, RUQ, pain, fatigue, N/V, light colored stool)
What tests monitor kidney fxn?
BUN, Creatinine, GFR, creatinine clearance (24 hr urine sample +blood)
What do you use to monitor bone marrow fxn?
CBC (complete blood count)
What toxic drug interaction can occur with heart?
- drugs that increase QT interval increase risk of dysrhythmia
- can lead to Torsades de Point
- > 100 drugs can cause
What percent of ADR are allergic reactions?
<10%
When do you have an allergic reaction (which exposure)?
on 2nd exposure
Intensity of drug reaction is _____ of dose causing it
independent
*trigger is independent of dose
3 Key drugs that cause allergic reaction
- penicillin
- NSAIDS
- sulfa (sulfanamides, sulfanylureas)
Difference between a mild and a severe allergic reaction
mild: itching, rash
severe: bronchospasm, decrease BP, laryngeal edema, life threatening
What is the paradoxical effect?
response is opposite of intended response
ex: benedryl making kids hyperactive instead of sleepy
What isIatrogenic Disease ? What do you do to treat it?
a drug that gives patients sxs of a disease they don’t have
-stop drug and sxs go away
Physical vs psychological dependence
physical: sxs or withdrawal that go away when you ween off
psychological: do whatever is in your power to get substance
Teratogenic effect
-drugs causing fetal malformation/defects
Nurses role in ADR management/prevention
- anticipate ADR
- patient teaching
- medication guides
- increase awareness for pt with choric disorders
- black box warnings
- med watch
____ drugs cause _____% of medication errors
20, 80%
1999 IOM report shows 3 main causes for medication error
- human error
- communication mistakes
- name confusion
1 cause of human error is
performance deficit (30%)
Window for drug administration
30 min before - 30 min after due
Other factors to help prevent med error
- TALLman lettering
- SALAD drugs
- medication zone/sash
- computer order entry
- bar code administration
- read back verbal orders
- do not crush list
- medication reconcilliation
