Flashcards in Antiemetic Agents Deck (31):
Describe the brainstem "vomiting center"
Coordinates the act of vomiting through CN VIII, X, & networks in the nucleus tractus solitarius
High concentrations of M1, H1, NK1, D2, GABA, & sertonin (5-HT3) receptors
What are the 4 sources of afferent input to the vomiting center?
1. "Chemoreceptor trigger zone" (D2, opioid, NK1, & 5-HT receptors)
2. Vestibular system (M1 & H1 receptors)
3. Vagal & spinal afferent nerves (5-HT receptors)
What drug classes are used to relieve vomiting? (6)
5 HT receptor antagonists
Substance P/Neurokinin 1 receptor antagonist
What do all 4 of the serotonin 5-HT3 antagonists end in?
Do you need to reduce the dose of serotonin 5-HT3 antagonists in geriatric patients or patients w/ renal insufficiency?
Which serotonin 5-HT3 antagonist may require dose reduction in patients w/ hepatic insufficiency?
What is an action of serotonin 5-HT3 antagonists?
May slow colonic transit
Describe the efficacy of serotonin 5-HT3 antagonists for the prevention of delayed N/V (> 24hr after chemo) when used alone
Little to none
How is the efficacy of serotonin 5-HT3 antagonists enhanced?
By combining w/ a corticosteroid & NK-receptor antagonist
What are ADEs of serotonin 5-HT3 antagonists?
HA, dizziness, constipation
QT prolongation (most pronounced w/ dolasetron)
What can other drugs do to the 5-HT3 receptor antagonists?
Reduce hepatic clearance --> increased 1/2 life
What are the actions of substance P/neurokinin 1 receptor antagonists?
Provide relief from delayed emesis a/w emetogenic meds
Possess antidepressant, anxiolytic, & antiemetic properties
What are ADEs of dimenhydrinate (Dramamine - an antihistaminic/anticholinergic)?
Drowsiness, confusion, blurred vision, dry mouth, urinary retention
What are examples of phenothiazines?
What are ADEs of prochlorperazine?
What is the MOA of chlorpromazine (a phenothiazine)?
Strong alpha-adrenergic blocker
Hypothalamic depression affecting body temp
What do the substance P/NK1 receptor antagonists end in?
Why is dimenhydrinate (an antihistaminic/anticholinergic) problematic in the elderly?
Risk of complications in patients w/ BPH, glaucoma, or asthma
What are examples of butyrophenones?
What are ADEs of haloperidol?
What are ADEs of droperidol?
QT prolongation &/or torsade de pointes
*Need 12 lead EKG prior to administration, followed by cardiac monitor for 2-3 hrs after administration
What are examples of benzos?
What are benzos used for?
Anticipatory N/V, chemo
What are ADEs of alprazolam?
What is the MOA of dexamethasone (a corticosteroid)?
Enhance 5-HT3 receptor antagonists
What are ADEs of dexamethasone?
What are examples of cannabinoids?
What are the ADEs of cannabinoids?
What are ADEs of metoclopramide?
Asthenia, HA, somnolence
What is an ADE of olanzapine?
Caution in elderly