How should Mounjaro (tirzepatide) be managed in a patient undergoing surgery?

Perioperative Management of Mounjaro (Tirzepatide) for Surgery

Tirzepatide (Mounjaro) should be temporarily discontinued before surgery due to its effect on gastric emptying, which may increase the risk of pulmonary aspiration during anesthesia. 1

Preoperative Management

• For patients on weekly Mounjaro (tirzepatide), discontinue the medication at least one week before elective surgery due to its long half-life of 5 days and potential to delay gastric emptying 2
• Inform anesthesia providers that the patient is taking Mounjaro, as this medication may cause slower gastric emptying which can lead to complications during anesthesia or deep sedation 1
• Monitor blood glucose levels closely before surgery, aiming for a target range of 5-10 mmol/L (90-180 mg/dL) 2
• Consider that even with discontinuation, some effects on gastric emptying may persist due to tirzepatide's long half-life 2
• For emergency surgeries where Mounjaro cannot be discontinued in advance, inform the anesthesiologist to take additional precautions regarding aspiration risk 2

Risk Assessment Considerations

• Evaluate the risk-benefit ratio of discontinuing Mounjaro, considering:
  • The urgency of the procedure (elective vs. emergency) 2
  • The type of anesthesia planned (general vs. regional) 2
  • The patient's glycemic control 2
  • The risk of pulmonary aspiration (OR 10.23 in elective surgical settings for GLP-1 RAs) 2

Intraoperative Management

• Monitor blood glucose levels hourly during surgery, especially for lengthy procedures 2
• Maintain blood glucose targets between 5-10 mmol/L (90-180 mg/dL) during surgery 2
• If blood glucose exceeds 10 mmol/L (180 mg/dL), administer rapid-acting insulin as needed 2
• Consider rapid sequence induction for general anesthesia due to the potential increased risk of aspiration, even if Mounjaro was discontinued 2
• For patients requiring insulin during surgery, use ultra-rapid acting insulin administered continuously via intravenous electronic syringe (IVES) in association with IV glucose 2

Postoperative Management

• Resume oral feeding as soon as possible 2
• Continue frequent blood glucose monitoring in the postoperative period 2
• Restart Mounjaro once the patient has fully recovered from anesthesia and is eating normally, typically at the next regularly scheduled dose 1
• If a dose is missed due to surgery, administer it as soon as possible within 4 days after the missed dose; if more than 4 days have passed, skip the missed dose and administer at the next regularly scheduled time 1
• Be vigilant for hypoglycemia, especially if the patient is on other glucose-lowering medications 3

Special Considerations

• For ambulatory surgery patients on Mounjaro, ensure blood glucose is <10 mmol/L (180 mg/dL) before discharge 2
• If blood glucose is >10 mmol/L (180 mg/dL) postoperatively, the patient should remain in hospital for monitoring and treatment 2
• For patients with poorly controlled diabetes (HbA1c >9%), consider postponing elective surgery until better control is achieved 2
• Be aware that Mounjaro may reduce the efficacy of oral hormonal contraceptives for female patients of reproductive age 1

Management of Complications

• For hypoglycemia (<3.3 mmol/L or 60 mg/dL), administer glucose immediately even without symptoms 3
• For unconscious patients with hypoglycemia, use intravenous glucose administration 3
• For severe hyperglycemia (>16.5 mmol/L or 300 mg/dL), investigate for ketosis in type 1 diabetes patients and consider insulin therapy 2
• Monitor for signs of dehydration due to potential gastrointestinal adverse reactions from Mounjaro 1

By following these guidelines for perioperative management of Mounjaro, clinicians can minimize the risks of aspiration during anesthesia while maintaining appropriate glycemic control throughout the surgical period.