How many days should a patient stop a GLP‑1 (glucagon‑like peptide‑1) receptor agonist before undergoing spinal surgery?

Preoperative GLP-1 Receptor Agonist Discontinuation for Spinal Surgery

For spinal surgery, discontinue GLP-1 receptor agonists for at least 3 weeks (approximately 21 days) before the procedure to minimize aspiration risk from delayed gastric emptying. 1, 2

Evidence-Based Holding Period

The recommendation to hold GLP-1 receptor agonists for three half-lives is based on pharmacokinetic principles that clear approximately 88% of the drug from the system 1, 2. For the most commonly prescribed agents:

• Semaglutide (Ozempic, Wegovy): 3 weeks before surgery 2, 3
• Tirzepatide (Mounjaro, Zepbound): 3 weeks before surgery 2, 3
• Dulaglutide (Trulicity): 2-3 weeks before surgery 2
• Liraglutide (Victoza, Saxenda): 3-4 days before surgery 2

Critically, the American Society of Anesthesiologists' initial recommendation of holding weekly agents for only 1 week has been shown to be inadequate, as discontinuation for 7 days did not decrease the prevalence of retained gastric contents 2, 3.

Why Three Weeks Matters

Multiple studies demonstrate that GLP-1 receptor agonists significantly delay gastric emptying even with extended fasting periods 1, 2:

• 24.2% of patients on semaglutide had residual gastric content compared to 5.1% of controls, despite 12+ hour fasting and 10-14 days of medication discontinuation 2
• Case reports document pulmonary aspiration requiring ICU admission in patients who fasted 18-20 hours and stopped semaglutide only 4-6 days before surgery 2
• Gastric emptying delays persist through multiple mechanisms: inhibition of gastric peristalsis, increased pyloric tone, and vagal pathway activation 1, 2

Special Considerations for Diabetic Patients

For patients taking GLP-1 receptor agonists for type 2 diabetes, consult with the treating endocrinologist regarding:

• Risks and benefits of holding the drug for at least three half-lives 1, 2
• Recommendations for bridging diabetic therapy if the GLP-1 receptor agonist must be held longer than the next scheduled dosing time 1, 2
• The benefits of glycemic control in the perioperative period may outweigh issues related to delayed gastric emptying in some diabetic patients, requiring individualized risk-benefit assessment 2

For patients using GLP-1 receptor agonists solely for weight loss, hold for the full 3 weeks without exception, as the risks of continuing until shortly before surgery outweigh any benefits 1, 2.

Risk Mitigation When Adequate Holding Period Not Achieved

If the patient cannot hold the medication for three half-lives (e.g., urgent spinal surgery), implement these strategies 1, 2:

• Consider postponing elective procedures to allow adequate medication clearance 1, 2
• Perform point-of-care gastric ultrasound pre-operatively to assess for residual gastric contents (target gastric volume <1.5 ml/kg) 1, 2
• Administer prokinetic drugs such as metoclopramide or erythromycin pre-operatively 1, 2
• Implement rapid-sequence intubation with full airway protection rather than supraglottic airways, as case reports document aspiration with supraglottic devices 2
• Consider pre-emptive gastric decompression in very high-risk patients 1
• Treat as "full stomach" case with appropriate aspiration precautions 2, 4

Additional High-Risk Scenarios Requiring Extra Caution

Patients in these categories may require even longer discontinuation periods or additional precautions 1, 2:

• Recently started medication or increased dose
• Experiencing nausea, vomiting, or abdominal distention
• Taking concomitant medications that delay gastric emptying (opioids, proton pump inhibitors, tricyclic antidepressants)
• Recent intake of recreational drugs that delay gastric emptying (alcohol, cannabis)
• Previous gastro-oesophageal surgery

Critical Pitfall to Avoid

Do not assume that standard fasting guidelines alone are sufficient for patients on GLP-1 receptor agonists—retained gastric contents persist despite extended fasting 2. Approximately 88% of the drug is cleared after three half-lives, but there is no strong evidence that gastric emptying fully normalizes after this time, so continued vigilance is required 2.