Metoclopramide Use in Patients with History of Gastric Bypass
Metoclopramide (Reglan) is generally safe and can be beneficial in patients with history of gastric bypass surgery, particularly as a prokinetic agent to improve gastric emptying and reduce postoperative nausea and vomiting. 1
Rationale for Use in Post-Gastric Bypass Patients
Metoclopramide offers several benefits for patients who have undergone gastric bypass:
- Enhances gastric emptying, which may be impaired following bariatric surgery
- Reduces nausea and vomiting, which are common complications after gastric bypass
- Acts as an adjunctive therapy for postoperative pain management 1
Evidence Supporting Use
The 2024 Anaesthesia guidelines specifically recommend considering prokinetic drugs such as metoclopramide pre-operatively for patients with history of gastric surgery, including those who have undergone bariatric procedures 1. This recommendation is particularly relevant for reducing aspiration risk in these patients.
Research has shown that the combination of metoclopramide with ondansetron is particularly effective in reducing post-operative nausea and vomiting (PONV) after bariatric surgery, with lower incidence of PONV (46.1%) compared to control groups (53.8%) 2.
Clinical Considerations
When administering metoclopramide to patients with gastric bypass:
Dosing considerations:
- Standard dosing is typically appropriate (10mg IV/PO)
- For IV administration, administer slowly over 1-2 minutes to avoid transient anxiety and restlessness 3
Timing of administration:
- Most effective when given 30-45 minutes prior to anesthesia induction when used pre-operatively 4
- Can be used postoperatively as needed for nausea, vomiting, or to promote gastric emptying
Monitoring requirements:
- Watch for extrapyramidal symptoms, which can occur with metoclopramide use
- Monitor for adequate pain control when used as an adjunct to pain management 5
Important Precautions
While generally safe, there are some precautions to consider:
Theoretical concern: Metoclopramide could potentially put increased pressure on suture lines following gut anastomosis 3. However, this theoretical risk is outweighed by the benefits of preventing postoperative nausea and vomiting in most cases.
Contraindications: Should not be used if there is concern for gastrointestinal hemorrhage, mechanical obstruction, or perforation 3, which could potentially occur as complications after gastric bypass.
Evidence from Specific Studies
A 1976 study demonstrated that metoclopramide produced a 2.6-fold increase in gastric emptying in patients with chronic gastric retention after vagotomy and gastric resection 6, suggesting particular benefit in patients with altered gastric anatomy.
Conclusion
Metoclopramide is not only safe but potentially beneficial in patients with history of gastric bypass surgery. It improves gastric emptying, reduces nausea and vomiting, and can be an important component of perioperative management in these patients.