ACEM Primary
Antiemetic Pharmacology
| Drug | MOA | |
| Ondansetron | 5-HT3 R blockade in gut and CNS (CTZ and vomiting centre) Mainly peripheral action on extrinsic vagal and spinal afferents | IV/ PO 4-9 hour duration of action Hepatic metabolism AE = dizziness, constipation, prolongation QT |
| Metoclopramide | Prokinetic agent D2 R blockade in gut and CNS Peripherally – increases oesophageal motility, increases lower oesophageal sphincter pressure, increases gastric emptying Centrally – acts at chemoreceptor trigger zone (CTZ) of medulla | IV/ PO AE = restlessness, drowsiness, extra pyramidal side effects, hyperprolactinaemia, galactorrhea |
| Corticosteroids: | Dexamethasone Inhibition of PG synthesis Exact mechanism unknown | IV/PO 4-8mg |
| Anti-muscarinics: Scopolamine | Block muscarinic R Effective at preventing sea sickness | AE = sedation, dry mouth |
| First generation anti-histamines: Diphenhydramine Cyclizine Doxylamine | H1 R antagonist Effective at preventing motion sickness | AE = sedation, anti-parkinsonism effects, anti-muscarinic effects, alpha blocking actions |
Last Updated on August 12, 2021 by Andrew Crofton
Andrew Crofton
0
Tags :