Nausea and vomiting

• What are common causes of nausea and vomiting?

  Ingestion of irritants, neurotoxins, viruses, motion sickness, and psychological stimuli.
• How does motion sickness occur?

  It occurs due to an alteration between visual stimuli and proprioception.
• What major problems can lead to nausea and vomiting?

  Major problems include cytoreductive therapy, chemotherapy, radiation, and post-operative issues.
• What is the vomiting center and its function?

  • Located within the medulla oblongata
  • Initiates the vomiting reflex
  • Expresses several neurotransmitter receptors (histamine, 5-HT, muscarinic, NK2)
• What is the chemoreceptor trigger zone (CTZ)?

  It is an area within the medulla oblongata that signals the vomiting center.
• Why is the chemoreceptor trigger zone sensitive to blood-borne stimuli?

  Because it is located outside the blood-brain barrier.
• What is the process of triggering the vomiting reflex through peripheral stimuli?

  1. Trigger chemoreceptor cells release 5-HT via afferent sensory nerve endings.
  2. Stimulate 5-HT3 receptors.
  3. Activate nerves that send signals to the vomiting center.
• What is chemotherapy-induced nausea and vomiting (CINV)?

  CINV is a condition caused by chemotherapy that leads to nausea and vomiting.
• When can postoperative nausea and vomiting occur?

  It can occur 14-48 hours after surgery.
• What are the types of antiemetics used for nausea and vomiting?

  1. Antihistamines (e.g., diphenhydramine)
  2. Antagonists (e.g., ondansetron)
  3. Neurokinin-1 receptor antagonists (e.g., aprepitant)
  4. Cannabinoids (e.g., dronabinol)
• How do 5-HT3 antagonists work in treating nausea and vomiting?

  They act at the CTZ and gastrointestinal tract to prevent nausea and vomiting.
• What are some non-pharmacological methods to manage nausea and vomiting?

  • Acupressure
  • Massage
  • Acupuncture
  • Electrical stimulation
• What is recommended for managing nausea during pregnancy?

  Ginger, acupressure, and antihistamines are recommended for managing nausea during pregnancy.