Severe Adverse Effects of Tirzepatide Overdose Requiring Intensive Care Unit Admission and Complex Rehabilitation.

Tirzepatide, a dual glucagon-like peptide-1 (GLP-1)/glucose-dependent insulinotropic polypeptide receptor agonist, is increasingly prescribed privately in the United Kingdom for weight loss. While gastrointestinal side effects are well recognized, severe metabolic derangements and hematological complications remain rarely documented. We report the case of a 39-year-old man with no significant comorbidities who developed life-threatening hypoglycemia, profound electrolyte abnormalities, pancytopenia, and aspiration pneumonia following unsupervised rapid dose escalation of tirzepatide used for weight loss. His clinical course was complicated by respiratory failure, septic shock, multiorgan dysfunction, and prolonged intensive care unit stay requiring mechanical ventilation, renal replacement therapy, tracheostomy, and complex neurorehabilitation. This case highlights the critical complications associated with inappropriate tirzepatide dosing and underscores the need for clinician vigilance and patient education as GLP-1 receptor agonist use continues to rise in the community.