Adverse Drug Effects & Drug Interactions

Side effects

a predictable usually mild effect that occurs alongside therapeutic effects at normal therapeutic doses. expected and then often tolerable

adverese effect

unwanted, an unintended undesirable and potentially harmful response to a drug at a normal dose, not the goal and often requires intervention

toxic effect

dangerous, harmful effets resulting from an excessive drug level in the body - often from overdose accumulation or impaired clearance,

spectrum of an allergic drug reaction

1 mild, 2 moderate, 3 severe, 4 anaphylaxis

mild, 1

pruritus (itching), urticaria (hives), or flushed skin

moderate, 2

angioedema - swelling of the lips, tongue, or throat

severe, 3

difficulty breathing, wheezing, or difficulty swallowing

anaphylaxis, 4

hypotension, airway compromise - life threatening emergency

drug allergy

immune response, different from side effect, body is reacting to the drug as a foreign threat not just experiencing its pharmacologic action

anaphylaxis

systemic life threatening allergic rxn, not side affect that can wait

classic findings of anaphylaxis

uticaria, angiodema, wheezing or stridor, hypertension, tachycardia, sense of impending doom,

first priority anaphylaxis

stop the suspected medication immediately if its still infusing or being administered

next step anaphylaxis

call for help, and preparing support airway, breathing, and circulation. kind of emergency where you access and act simultaneously not sequentially

documenting anaphylaxis

throughly once the pt is stabilized and ensure the allergy is clearly flagged in the medical record so its never repeated

contrainindication

condition or factor that makes a specific drug inapproperiate or dangerous to give at all

example of contraindications

documented anaphylactic penicillin allergy contraindicates giving penicillin

precaution

condition that doesnt dule the drug out entirely, but requires extra caution, dose adjustment or closer monitoring

example of precaution

renal impairment is precaution for a renally cleared drug, not necessarily a contraindication

If a drug has a contraindication or serious precaution applies

nurse responsibility to hold the meds and consult the provider .

additive effect

two drugs w/ similar actions combine to produce an effect roughly equal to a sum of the each (two CNS depressants increasing sedation)

synergistic effect

two drugs combine to produce an effect greater than the simple sum of their individual effects (often more dangerous than additive interactions)

potentiation

one drug enhances the effect of second drug without necessarily having much effort of its own at the receptor

antagonism/ imcopatibility

one drug blocks or reduces the effect of another

drug food interactions

grapefruit juce, vitamine k rich foods, tyramine rich foods, dairy products

grapefruit juice (v. common)

inhibits liver enzyme (CYP3A4), raising blood levels of many drugs, including some statins and calcium channel blockers

vitamin k rich foods

leafy greens can reduce the effectiveness of warfarin

warfarin

anticoagulant that works by opposing vitamin K

tyramine rich foods

aged cheese, cured meats, fermented foods can trigger hypertensive crisis in patient taking MAOIs (monoamine oxidase inhibitor)

MAOIs (monoamine oxidase inhibitor)

antidepression and sometimes in pt with parkinsons

dairy products

calcium can bind to certain antibiotics (like tetracyclines) and significantly reduce their absorption

drug herbal interactions

st. john’s worts, ginkgo biloba, garlic supplements, ginseng

st johns worts

induced liver enzymes, reducing blood levels of many drugs including oral contraceptives and antidepressants

ginkgo biloba

increase bleeding risk when combined with anticoagulants or antiplatelet drugs

garlic supplements

carries antiplatelet activity and can compound bleeding risk with warfarin or aspirin

ginseng

may interact with anticoagulants and can alter blood glucose control in patients on antidiabetic medications

interactions coumpound with polypharm

through med list/ history (OTC, perscription, and herbal) in order to screen for interactions before it happens, pharmacy and clinical systems can flag interactions autimatically if meds are accurate

Nursing strategie to present harm

HLMR

H nuring strategy

take complete medication history

L in nursing strategies

look up unfamiliar combinations

M in nursing strategies

monitor after administration

r in nursing strategies

report and reconcile

What category of interaction does this scenario most likely represent, and why might an antibiotic affect warfarin's activity?

antibiotics alter absorptions, distribution, metabolism, or excretion. most common mech is hepatic enzyme inhibition

What should the nurse's next actions be, given these findings?

Stop medications, assess, notify provider

How could this interaction have been anticipated earlier in the medication reconciliation process?

screening with polypharmacy, correct med reconciliation