Drug class and drug | Mechanism of action | Indications | Side effects |
Antihistamines | Minimal antiemetic activity | ||
Diphenhydramine | Vestibular suppression, anti-ACh effect, and H1 antagonist | Motion sickness. | Sedation, anti-ACh effects* |
Hydroxyzine | |||
Dimenhydrinate | |||
Meclizine | |||
Antipsychotics | Mild to moderate antiemetic activity | ||
Promethazine | D2 antagonist at CTZ and H1 antagonist | Chemotherapy-induced vomiting. | Anti-ACh effects*, extrapyramidal reactions, QTc prolongation |
Prochlorperazine | D2 antagonist at CTZ | ||
Chlorpromazine | |||
Olanzapine | D2 antagonist at CTZ, 5-HT6 antagonist | ||
Substituted benzamides | Moderate antiemetic activity | ||
Metoclopramide | D2 antagonist at CTZ and 5-HT4 agonist in gut | GERD; gastroparesis; chemotherapy-induced vomiting. | Irritability and extrapyramidal reactions |
Trimethobenzamide | D2 antagonist at CTZ | ||
Cisapride | 5-HT4 agonist, ACh release in gut | GERD; gastroparesis. | Diarrhea, abdominal pain, headache, QT prolongation |
Benzimidazole derivatives | Moderate antiemetic activity | ||
Domperidone | D2 antagonist in gut | Gastroparesis; chemotherapy-induced vomiting. | Headaches; not available in the United States |
5-HT3 receptor antagonists | High antiemetic activity | ||
Ondansetron | 5-HT3 antagonist at CTZ and decreases vagal afferents from gut | Chemotherapy- and postoperative-induced vomiting; cyclic vomiting syndrome. Ondansetron has also been used in the treatment of acute gastroenteritis. Ondansetron comes in PO, IM, and IV formulations. All others are IV formulations only. Palonosetron has a longer half-life (40 hours).
| Headache |
Granisetron | |||
Tropisetron | |||
Dolasetron | |||
Palonosetron | |||
Tachykinin receptor antagonists | High antiemetic activity | ||
Aprepitant | NK1 antagonist, acts on emetic program | Chemotherapy-induced vomiting (effect is on delayed phase, >24 hours); cyclic vomiting syndrome. | Fatigue, dizziness, diarrhea |
Anticholinergics | Minimal to mild antiemetic activity | ||
Scopolamine | Vestibular suppression, anti-ACh | Motion sickness. | Sedation, anti-ACh effects* |
Butyrophenones | Moderate antiemetic activity | ||
Droperidol | D2 antagonist at CTZ; anxiolytic action and sedation | Chemotherapy- and postoperative-induced vomiting. | Hypotension, sedation, extrapyramidal effects |
Benzodiazepines | Minimal antiemetic activity | ||
Lorazepam | Enhanced central GABA-ergic signaling; induces anxiolysis, sedation, and amnesia | Adjunctive therapy (sedation) for chemotherapy-induced vomiting and cyclic vomiting syndrome¶. Diazepam may be given rectally. | Sedation, respiratory depression |
Diazepam | |||
Antimigraine-abortive triptans | |||
Sumatriptan | 5-HT1B1D agonist; induces cerebral vasoconstriction, relaxes gastric fundus | Abortive approach for migraine, abdominal migraine, cyclic vomiting syndrome¶. Subcutaneous, PO, nasal and rectal formulations. | Transient burning sensation in chest and neck |
Zolmitriptan | PO, ODT, and nasal formulations. | ||
Frovatriptan | PO formulation; longer half-life (26 hours). | ||
Rizatriptan | ODT formulation. | ||
Other – NSAIDs | |||
Ketorolac | Cyclooxygenase inhibitor of prostaglandin synthesis | Abortive approach for migraine, cyclic vomiting syndrome¶. | Gastrointestinal bleeding |
Antimigraine – prophylactic medication | |||
Cyproheptadine | H1 antagonist and 5-HT2 antagonist | Prevention of migraine, abdominal migraine, cyclic vomiting syndrome. | Sedation, anti-ACh effects*, weight gain due to appetite stimulation |
Pizotifen, pizotyline | 5-HT2 antagonist | Not available in the United States | |
Propranolol | β1, β2 adrenergic antagonist | Prevention of abdominal migraine, cyclic vomiting syndrome. | Hypotension, bradycardia, fatigability; monitor pulse |
Amitriptyline, nortriptyline | 5-HT2 antagonist, increases synaptic norepinephrine | Prevention of migraine, abdominal migraine, cyclic vomiting syndrome¶. | Sedation, anti-ACh effects*, QTc prolongation |
Corticosteroids | |||
Dexamethasone | Unknown | Adjunctive therapy for chemotherapy- and postoperative-induced vomiting. | Adrenal suppression |
Cannabinoids | |||
Dronabinol | Acts on CB1R receptors on vagus | Chemotherapy-induced vomiting. | Disorientation, vertigo, hallucinations |
Nabilone |
ACh: acetylcholine; H: histamine; D: dopamine; CTZ: chemoreceptor trigger zone; 5-HT: 5-hydroxytryptamine (serotonin); GERD: gastroesophageal reflux disease; PO: orally; IM: intramuscularly; IV: intravenously; NK: neurokinin; GABA: gamma-aminobutyric acid; ODT: orally dissolving tablet; NSAID: nonsteroidal antiinflammatory drug; CB1R: cannabinoid receptor 1.
* Anticholinergic effects include blurred vision, dry mouth, hypotension, palpitations, and urinary retention.
¶ Pharmacotherapy for cyclic vomiting syndrome may be preventive, supportive, or abortive, depending on the patient's characteristics. For detailed guidance, refer to UpToDate content and tables on cyclic vomiting syndrome.