GI part 1.txt

  1. Vomiting (AKA emesis)
    • protective mechanism in reponse to some trigger such as:
    • irritants
    • infection
    • distention
    • blockage
    • motion sickness
    • umpleasant sight or smell
  2. Sympathetic responses to nausea
    • increased respiration
    • dilation of pupils
  3. Parasympathetic responses to nausea
    • profuse salivation
    • pronounced motility of the esophagus, stomach and duodenum
    • relaxation of the esophageal sphincter
  4. The process of vomiting
    • person takes a deep breath
    • pylorus closes
    • glottis closes so respiration stops
    • stomach is squeezed between the diaphragm and abdominal muscles, causing rapid emptying
  5. Neurotransmitters involved in nausea and vomiting
    • H1 (histamine1) receptors
    • M1 (muscarinic1) receptors
    • D2 (dopamine2) receptors
    • serotonin (5-hydroxytryptamine3 5_ht3) receptors
    • NK1 (neurokinin1) receptors
    • CB1 (cannabinoid1) receptors
    • antagonists for all of these used for treatments
  6. H1 receptor antagonists
    antiemetic and antispasmodic activity by blocking H1 receptors
  7. M1 (Muscarinic 1) receptor antagonists
    • work by correcting the imbalance of acetylcholine and norepinephrine that can occur in motion sickness
    • block signals to the brain that cause nausea and vomiting
  8. D2 (Dopamine 2) receptor antagonists
    • not used as an antipsychotic therapy
    • block D2 receptors in the chemoreceptor trigger zone (CTZ)
    • effects are similar to both H1 and M1 receptor antagonists
  9. 5-HT3 (Serotonin) receptor antagonists
    prevent nausea/vomiting due to cancer chemotherapy or surgery by blocking 5-HT3 receptors in CTZ
  10. NK1 (Neurokinin1) receptor antagonists
    used to prevent and treat acute and delayed nausea and vomiting associated with chemotherapy
  11. CB1 (Cannabinoid1) receptor antagonists
    antiemetic action of CB1 receptor agonists is due to stimulation of CB1 receptors in the vomiting center
  12. Adjunct therapies used in combination with antiemetics
    • benzodiazepines (prevent nausea and vomiting associated with chemo)
    • glucocorticosteroids (augment antiemetic effect of %-HT3 receptor antagonist during chemo)
  13. Benzquinamide
    antagonizes both muscarinic and H1 receptors in CTZ to decrease vomiting center activity
  14. Diphenidol
    controls dizziness, nausea and vomiting associated with Meniere's disease, ear surgery and ear disorders
  15. Trimethobenzamide
    may inhibit CTZ where emetic impulses are sent to the vomiting center
Card Set
GI part 1.txt
GI part 1, nausea and vomiting