gi drugs (antiemetic agents) -> brain boost

class for the prototype promethazine

phenothiazines

prototype for the class phenothiazines

promethazine

promethazine mech

blocks dopamine receptors in CTZ; has antihistamine properties to reduce nausea and vomiting

promethazine therapeutic use

treatment of N/V related to surgery, chemo, motion sickness

promethazine adverse effects

drowsiness, dizziness, hypotension, cardiac arrhythmias, photosensitivity, endocrine effects

promethazine nursing considerations

avoid concurrent CNS depressants or alcohol; use with caution in those with liver disease; avoid children under 2 (respiratory depression risk)

promethazine client instructions

protect skin from sun, report involuntary movements, palpitations, severe drowsiness; avoid hazardous activities and driving

prototype for the class dopamine antagonist/ prokinetic agent

metoclopramide

class for the prototype metoclopramide

dopamine antagonist/ prokinetic agent

metoclopramide mech

blocks dopamine receptors and increase acetylcholine sensitivity; enhances GI motility and gastric emptying

metoclopramide therapeutic use

GERD, diabetic gastroparesis, chemo related n/v

metoclopramide adverse effects

sedation, restlessness, diarrhea, tardive dyskinesia; neuroleptic malignant syndrome

metoclopramide nursing considerations

administer 30 min before meals and at bedtime; avoid alcohol; discontinue if tremors or facial spasms occur

metoclopramide client instructions

change positions slowly; report involuntary movements and avoid driving

prototype for the class serotonin (5-HT3) receptor blockers

ondansetron

class for the prototype ondansetron

serotonin (5-HT3) receptor blockers

ondansetron mech

blocks serotonin receptors in CTZ and GI tract; prevents stim of vomiting center

ondansetron therapeutic use

N/V associated chemo, radiation, postoperative recovery

ondansetron adverse effects

headache, dizziness, myalgia, constipation or diarrhea, hypotension, QT prolongation

ondansetron nursing considerations

administer IV slowly over 15 mins; 30 min before chemo; avoid in clients w/ congenital long QT syndrome

ondansetron client instructions

take 30-60 min before chemo; report headache; rise slowly; drink fluid to prevent dehydration

prototype for the class substance P/ neurokinin-1 receptor antagonists

aprepitant

class for the prototype aprepitant

substance P/ neurokinin-1 receptor antagonists

aprepitant mech

blocks neurokinin-1 receptors in CNS; prevents emesis signals

aprepitant therapeutic use

prevention of acute/ delayed nausea and vomiting associated with chemo

aprepitant adverse effects

fatigue, dizziness, diarrhea, elevated liver enzymes

aprepitant nursing considerations

monitor liver function tests; use backup contraception; monitor INR if on warfarin

aprepitant client instructions

report dizziness; use alternative birth control; report yellowing of skin or eyes; avoid alcohol