Demographics and outcome of unintentional insulin overdoses managed by three poison centers

Insulin dosing errors are one of the most dangerous medication issues due to the risk of profound hypoglycemia. The incidence of insulin dosing errors is increasing and there is no standard of care for management location.

To determine the types of insulin, follow-up time, number of phone calls, incidence of hypoglycemia, and case outcomes for unintentional insulin overdoses managed by Poison Centers (PCs).

Observational case series: records of patients with unintentional injected insulin errors from three PCs over a 22-month period were manually reviewed for insulin type, management site, time of exposure, insulin dose, number of calls, presence of hypoglycemia, and case outcome.

There were 642 cases: 97.5% occurred in the home and the majority of patients (77.3%) were managed on site with only 17.4% resulting in Emergency Department treatment. Clinical or numerical (blood sugar < 60 mg/dL) hypoglycemia occurred 15.9% (n = 102) of the time in all cases, with 6.9% (n = 41) of cases having numerical hypoglycemia. The median insulin dose when known was 40 Units, with short-acting insulin making up the majority of cases (64.3%) with 13.8% of cases having a dose error of 80 or more units. The average duration of follow-up was 6.9 h. The frequency of hypoglycemia (clinical or numerical) did not differ between short and non-short duration insulin cases (15.7% vs. 16.9%, n = 65 vs. 37, p = 0.91), did not differ with cases receiving more than 50 Units of insulin (14.9% vs. 16.7%, n = 29 vs. 73, p = 0.64), and did not differ between those managed on site and other management locations (14.4% vs. 21.4%, n = 71 vs. 31, p = 0.053). Outcomes were benign in the majority of cases and there were no cases with Major (severe) outcomes or Death.

Insulin dosing accidents can be routinely managed at home by PCs and have a low rate of hypoglycemia and adverse outcomes. This suggests that these cases can often be managed at home without referral with a potential benefit in no direct cost to the patient, convenience, and immediacy.