A single study in the review reported that rectal dimenhydrinate was effective at reducing vomiting. 18 Intravenous ondansetron or metoclopramide also reduced vomiting and hospitalisation. 17Ī systematic review reported that oral ondansetron reduced vomiting, hospitalisation and the need for intravenous rehydration in children with acute gastroenteritis. Ondansetron is not recommended in children under six months of age or less than 8 kg in weight. Children weighing 8–15 kg should receive 2 mg, children weighing 15–30 kg should receive 4 mg and children weighing more than 30 kg should receive 8 mg. 17 These guidelines recommend a single weight-based dose of oral ondansetron. When an antiemetic drug is indicated, serotonin antagonists such as ondansetron are now recommended in guidelines, such as those published by the Royal Children’s Hospital Melbourne. Until the early 2000s, antiemetics including promethazine, metoclopramide and prochlorperazine were widely used in children, however their use is now controversial due to reports of adverse events including sedation and extrapyramidal reactions.

Nausea and vomiting resulting from acute gastroenteritis is particularly challenging in children. Therapeutic options available for adults with vomiting secondary to gastroenteritis include dopamine antagonists such as metoclopramide or prochlorperazine and serotonin antagonists such as ondansetron. Table 2 - Indications and scheduling for antiemetic drugsĪcute gastroenteritis is caused by viral, bacterial or protozoal infections. † Not currently registered as antiemetics in Australia * Also block serotonin, histamine, adrenergic and muscarinic receptors When combined with 5-HT 3 antagonists there are reduced serotonin concentrations in the gut and increased sensitivity of 5-HT 3 receptors to antiemetics.Īgonist action at the GABA A receptor provides anxiolysis.Īction at the chemoreceptor trigger zone to suppress the activity of dopamine.Īctivate cannabinoid CB1 (inhibitory) receptors in the central nervous system and peripheral nervous system to modulate release of neurotransmitters. Hyoscine (oral) – available as non-prescription medicine.Ĭentral inhibition of prostaglandin synthesis and encephalin release. Hyoscine (parenteral) – palliative care medicine. Promethazine also blocks dopamine D2 receptors.īlock muscarinic receptors in vestibular nuclei, vomiting centre and higher brain centres. Netupitant/palonosetron fixed-dose combinationīlock neurokinin type 1 receptors in the central and peripheral nervous system.Ĭyclizine, doxylamine, promethazine and pheniramine all block muscarinic receptors. Tropisetron – chemotherapy-induced nausea and vomiting Palonosetron – chemotherapy-induced nausea and vomiting Granisetron – chemotherapy or radiation- induced nausea and vomiting Ondansetron – chemotherapy or radiation- induced nausea and vomiting Metoclopramide and paracetamol combinations – available as non-prescription medicinesīlock 5-HT 3 receptors in the chemoreceptor trigger zone and gastrointestinal tract. Metoclopramide (parenteral) – palliative care medicine These include blockade of serotonin, histamine, adrenergic and muscarinic receptors. Phenothiazines – prochlorperazine,* chlorpromazine*īutyrophenones – droperidol,* haloperidol*īlock dopamine type 2 (D2) receptors centrally in the chemoreceptor trigger zone and peripherally in the gastrointestinal tract.ĭomperidone blocks peripheral D2 receptors only.Īt higher doses, effects on other receptors are seen. Pharmaceutical Benefits Scheme restrictions

Table 1 - Antiemetics available in Australia

Anti nausea medication