After high-dose insulin therapy for drug poisoning, insulin's elimination half-life was a median of 1.8 hours — much shorter than previously reported — with hyperinsulinemia resolving within 24 hours.
1.8-hour median half-lifePrevious studies reported insulin half-lives up to 18.8 hours after high-dose therapy, but this study found a median of just 1.8 hours, suggesting much faster clearance than expected.
What the researchers found
In 10 poisoned patients treated with high-dose insulin, the median elimination half-life of insulin after discontinuation was 1.8 hours (IQR 1.4–4.0 h; range 1.23–9.8 h) — substantially shorter than previously reported values of up to 18.8 hours. The half-life was not significantly affected by insulin dosage, treatment duration, or kidney disease.
C-peptide (a marker of the body's own insulin production) tracked with blood glucose levels despite the high external insulin, and concentrations remained mostly within normal reference ranges, suggesting that glucose supplementation during treatment was not excessive. Hyperinsulinemia typically resolved within 24 hours of stopping high-dose insulin.
Why it matters
High-dose insulin is used to treat life-threatening drug poisonings that cause heart failure, but doctors have worried about prolonged low blood sugar risk after stopping treatment. This study shows that insulin clears from the body faster than previously thought, which could reduce unnecessary monitoring time and glucose supplementation, improving clinical management of poisoned patients.
How the study worked
A consecutive case series of 10 poisoned patients treated with high-dose insulin at a clinical toxicology center. Serial insulin and C-peptide blood concentrations were measured after discontinuing high-dose insulin. Apparent elimination half-lives were calculated using non-linear regression or simplified pharmacokinetic methods.
Who was studied
Poisoned patients treated with high-dose insulin for cardiogenic shock (1 with type 2 diabetes, 5 with acute kidney injury)
What this study cannot tell us
Very small sample size of only 10 patients limits generalizability. One patient had pre-existing diabetes, five developed acute kidney injury, and three required kidney replacement therapy — introducing heterogeneity. The case series design lacks a control group. Different poisoning agents across cases may affect insulin pharmacokinetics differently.
How to read the evidence
This is a consecutive case series of 10 patients — a small observational study without controls. While it provides useful clinical pharmacokinetic data, larger studies are needed to confirm these findings across diverse patient populations.
When this study was published
Published in 2026, this is a very recent study addressing a practical gap in clinical toxicology knowledge.
The bigger picture
High-dose insulin therapy for drug poisoning is increasingly used in emergency medicine, but clinical uncertainty about insulin clearance has led to prolonged monitoring and potentially excessive glucose supplementation. This study provides pharmacokinetic data that could streamline post-treatment care. It also demonstrates the value of C-peptide as a practical clinical biomarker for guiding glucose management decisions.
Questions still open
- Why are the half-life values in this study so much shorter than previously reported?
- Could routine C-peptide monitoring during dextrose weaning become standard practice in poisoning management?
- How do comorbidities like diabetes and kidney disease specifically alter insulin clearance in this clinical context?
Common questions
Why is high-dose insulin used to treat drug poisoning?
What is C-peptide and why was it measured in this study?
Read the original research
Serial insulin and C-peptide concentrations following high-dose insulin for the treatment of drug poisoning: a consecutive case series.
Clinical toxicology (Philadelphia, Pa.), 1-9
Citation
Nic Ionmhain, Úna; Coulson, Lori; Roberts, Darren M. (2026). Serial insulin and C-peptide concentrations following high-dose insulin for the treatment of drug poisoning: a consecutive case series.. Clinical toxicology (Philadelphia, Pa.), 1-9. https://doi.org/10.1080/15563650.2026.2613033