What should I do with a patient who is vomiting while taking long‑acting insulin (e.g., insulin glargine) and lisinopril?

Management of Vomiting Patient on Long-Acting Insulin and Lisinopril

Temporarily stop the lisinopril immediately and continue the long-acting insulin with dose adjustments based on blood glucose monitoring and oral intake status.

Immediate Medication Management

Lisinopril (ACE Inhibitor)

• Stop lisinopril temporarily for up to 3 days or until vomiting resolves 1
• ACE inhibitors should be held during acute illness with vomiting due to risk of volume depletion, hypotension, and acute kidney injury
• Resume at usual dose within 24-48 hours of normal eating and drinking 1

Long-Acting Insulin

Do NOT routinely stop the basal insulin - this is a critical distinction from other medications. The approach depends on:

If blood glucose is LOW:

• Hold the insulin dose until blood glucose recovers 1
• Monitor blood glucose every 4-6 hours while awake 1
• Once eating/drinking resumes and glucose normalizes, restart at usual dose 1

If blood glucose is NORMAL or ELEVATED:

• Continue the basal insulin - patients still have basal insulin requirements even when not eating
• Consider empirical 10-20% increase in insulin dose if glucose is more elevated than usual 1
• If unsuccessful at lowering blood glucose after adjustment, contact healthcare provider 1
• The long-acting effect of insulin glargine may delay recovery from hypoglycemia if it occurs 2

Monitoring Requirements

Mandatory glucose monitoring:

• Check blood glucose every 4-6 hours while awake for duration of symptoms 1
• More frequent monitoring if patient has reduced symptomatic awareness of hypoglycemia 2

When to Seek Immediate Medical Attention

Contact healthcare provider if:

• Vomiting >4 times in 12 hours or cannot keep fluids down 1
• Patient feels unable to cope with self-management 1
• Symptoms persist beyond 72 hours 1
• Recurrent low blood glucose readings 1
• Blood glucose significantly elevated and not responding to 10-20% dose increase after 24 hours 1

Seek emergency care (911) for:

• Reduced level of consciousness or new confusion 1
• Difficulty or rapid breathing 1
• Fainting or falls 1

Fluid Management

• Increase fluid intake with limited caffeine 1
• Consider electrolyte replacement solutions 1
• Adequate hydration is essential as insulin can cause potassium shifts and hypokalemia 2

Common Pitfalls to Avoid

1. Do not automatically stop basal insulin - unlike oral diabetes medications and ACE inhibitors, basal insulin provides essential background glucose control even during illness
2. Do not assume nausea/vomiting is unrelated to insulin - while rare, insulin glargine has been associated with nausea and emesis in case reports 3, though this is uncommon
3. Do not restart lisinopril too early - wait until patient has been eating and drinking normally for 24-48 hours 1
4. Do not delay seeking help - the 72-hour window for self-management is firm 1

Duration of Sick Day Management

• Self-management appropriate for maximum 72 hours 1
• All temporarily stopped medications should be resumed within this timeframe once symptoms resolve 1