| Question | Answer |
| what are areas in body that trigger vomiting | Vomiting center (VC)
Chemoreceptor trigger zone (CTZ)
Both located in the brain |
| what are three pathways that lead to CTZ | GI tract, labyrinth(inner ear), cerebral cortex |
| how do anticholinergics help as antiemetics | Bind to & block acetylcholine (ACh) receptors in the inner ear labyrinth
Block transmission of nauseating stimuli to CTZ
Also block transmission of nauseating stimuli from the reticular formation to the VC
scopolamine- used for motion sickness |
| how do antihistamines help as antiemetics | Inhibit ACh by binding to H1 receptors
Prevent cholinergic stimulation in vestibular and reticular areas, motion sickness, nonproductive cough, allergy symptoms, sedation
dimenhydrinate (Dramamine)
diphenhydramine (Benadryl)
meclizine (Antivert) |
| how do antidopaminergic help as antiemetics | Antidopaminergic drugs
Block dopamine receptors on the CTZ
Also used for psychotic disorders, intractable hiccups
prochlorperazine (Compazine)
promethazine (Phenergan)
droperidol (Inapsine): Use is controversial because of associated cardiac dysrhyth |
| how do prokinetic drugs help as antiemetics | Block dopamine in the CTZ
Also stimulate peristalsis in GI tract, enhancing emptying of stomach contents
Also used for GERD, delayed gastric emptying
metoclopramide (Reglan)- Long-term use may cause irreversible tardive dyskinesia |
| how do serotonin blockers help as antiemetics | Block serotonin receptors.
Used for patients receiving chemotherapy, postop nausea and vomiting. "On Dancer, On Prancer....Santa is bringin Zofran"
dolasetron (Anzemet), granisetron (Kytril), ondansetron (Zofran), palonosetron (Aloxi) |
| What are tetrahydrocannabinoids | Major psychoactive substance in marijuana
Inhibitory effects on reticular formation, thalamus, cerebral cortex
dronabinol (Marinol)
Used for nausea & vomiting associated with chemotherapy, & anorexia associated with weight loss in AIDS patients |
| what herbal products act as antiemetics | Ginger- chemo, morning sickness, motion sickness.
adverse effects: anorexia, N/V, skin reactions
May increase absorption of oral medications
Increase bleeding risk with anticoagulants |
| all antiemetics can do what | cause drowsy, dizzy, no alcohol, hypotension |
