N+V, constipation and breathlessness Flashcards
Causes of N+V
Infection Hypercalcaemia Opioids Renal/hepatic failure Gastric stasis Constipation Raised ICP Anxiety
What transmitters act on the chemoreceptor trigger zone in the postrema
NK1
Dopamine
Serotonin
What transmitters act on the vomiting centre in the postrema
NK1
ACh
Histamine
Serotonin
What transmitters act on the VIII nucleus
ACh
Histamine
What does haloperidol act on
Chemoreceptor trigger zone (very inhibitory)
What does metoclopramide act on
Chemoreceptor trigger zone
Vagus afferents
What does domperidone act on
Chemoreceptor trigger zone
What does cyclizine act on
Vomiting centre
VIII nucleus
What does ondansetron act on
Vagus afferents (very inhibitory)
Choice of anti-emetic for chemical causes of N+V
Haloperidol
Choice of anti-emetic for gastric stasis causes of N+V
Metoclopramide
Domperidone
Choice of anti-emetic for bowel obstruction causes of N+V
Cyclizine
Choice of anti-emetic for raised ICP causes of N+V
Cyclizine
Dexamethasone
Choice of anti-emetic for post-op and post-radiotherapy causes of N+V
Ondansetron
What is aprepitant and how is it used
NK1 antagonist
Regularly given SC for chemo induced N+V