Severe diabetic ketoacidosis linked to lower insulin doses after starting tirzepatide

A man in his 50s with insulin-treated type 2 diabetes developed severe diabetic ketoacidosis after starting tirzepatide.

• The patient experienced severe abdominal pain, nausea, and vomiting 15 days after initiating tirzepatide.
• He presented with profound high-anion gap metabolic acidosis (pH 6.8), marked hyperglycaemia, and ketosis.
• Prior to starting tirzepatide, he had no history of diabetic ketoacidosis despite long-term insulin treatment.
• Gastrointestinal symptoms worsened after the second dose of tirzepatide, leading to an inability to tolerate food or fluids.
• The patient reduced his insulin dosage due to concerns about hypoglycaemia during this period.
• Emphasis is placed on the need for patients to understand sick-day rules and continue basal insulin when starting tirzepatide.

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