Table 5. Prokinetic Agents for Gastroparesis Agent (Brand) Mechanism of Action
Comments
Metoclopramide (Reglan® generic)
,
Macrolide antibiotics (eg, erythromycin)
Domperidone (Motilium™
)
Bethanechol generic
• Central/peripheral dopamine receptor antagonist
• Also 5-HT3 • Also 5-HT4
antagonist agonist
• Motilin receptor agonist
• FDA approved for gastroparesis • CNS side effects in 20-30% • Prokinetic and antiemetic properties • Risk of tardive dyskinesia is < 1%
• Low doses are used – 125 mg po before each meal
• Gastrointestinal side effects in many: nausea/vomiting/abdominal pain
• Tachyphylaxis with long-term use (4 weeks)
• Peripheral dopamine receptor antagonist
• Muscarinic receptor agonist
• Prokinetic and antiemetic properties Available in Europe/Canada/Mexico/ New Zealand but not in the US
• Improves gastric emptying, no data on symptoms
• Increases amplitude of contractions, not peristalsis
• Not a true prokinetic agent
Table 6. Antiemetic Medications Class of Agent
Dopamine D2 -receptor antagonists
With prokinetic activity Without prokinetic activity
Tricyclic antidepressants
Benzodiazepines Neurokinin NK1
The H1 predominant activity. , D2 and M1 Metoclopramide, domperidone
Promethazine, prochlorperazine, trimethobenzamide, thiethylperazine
Serotonin 5-HT3-receptor antagonists Ondansetron, granisetron, dolasetron, tropisetron Desipramine, nortriptyline, amitriptyline Scopolamine, hyoscyamine, clinidium Tetrahydrocannabinol, Marinol® Lorazepam
Muscarinic receptor antagonists Cannabinoids
-receptor antagonists Aprepitant (for chemotherapy-induced or postoperative nausea or vomiting)
receptor antagonists have overlap. The classification reflects the
Examples
