Why should Mounjaro (tirzepatide) be withheld before surgery?

Why Mounjaro (Tirzepatide) Should Be Withheld Before Surgery

Mounjaro (tirzepatide) should be withheld before surgery because it significantly delays gastric emptying, which increases the risk of pulmonary aspiration during general anesthesia or deep sedation. 1, 2

Mechanism of Concern

Tirzepatide, as a dual GIP/GLP-1 receptor agonist, has potent effects on gastric motility:

• It substantially delays gastric emptying, which can lead to retained gastric contents despite adherence to standard fasting protocols 1
• The FDA label specifically warns about pulmonary aspiration risk during general anesthesia or deep sedation 2
• Studies show an increased risk of pulmonary aspiration with GLP-1 receptor agonists in surgical settings, with an odds ratio of 10.23 (95% CI: 2.94-35.82) 1

Recommended Withholding Period

The appropriate withholding period depends on the formulation of tirzepatide:

• For Mounjaro (weekly injection), withhold for at least one week before surgery 1
• This recommendation is based on tirzepatide's long elimination half-life of approximately 5 days 1
• The drug's effects on gastric emptying may persist beyond the pharmacokinetic half-life

Clinical Considerations

Several factors influence the decision to withhold Mounjaro:

1. Indication for use:

   • For patients using Mounjaro for weight management, withhold for at least three half-lives (approximately 15 days) before elective surgery 1
   • For patients with diabetes, balance the risk of aspiration against glycemic control needs 1

2. Surgical urgency:

   • For elective procedures, follow the recommended withholding period
   • For emergency procedures, inform the anesthesiologist about Mounjaro use for appropriate aspiration precautions 2

3. Anesthetic technique:

   • General anesthesia carries the highest risk of aspiration
   • Regional anesthesia with sedation still carries risk if deep sedation is required 1

Resuming Mounjaro After Surgery

• Resume Mounjaro only when:
  • The patient is eating and drinking normally
  • The surgical wound shows evidence of healing (typically ~14 days)
  • There are no signs of infection or complications 1
• If more than 4 days have passed since a scheduled dose, skip the missed dose and take the next dose on the regularly scheduled day 2

Important Caveats

• Even with proper withholding, patients may still have delayed gastric emptying due to tachyphylaxis effects 1
• Patients should always inform all healthcare providers about Mounjaro use before any planned surgeries or procedures 2
• The risk of aspiration must be balanced against potential deterioration in glycemic control when withholding the medication in patients with diabetes 1

The evidence clearly demonstrates that the risk of pulmonary aspiration during surgery is significant enough to warrant withholding Mounjaro before surgical procedures, with the withholding period based on the drug's long half-life and persistent effects on gastric motility.