EM PHARMACOLOGY
Reassessing Diabetic Ketoacidosis Treatment: Benefits of Early Subcutaneous Insulin
SAEM PULSE | MAY-JUNE 2025
By Vivian Kum, PharmD, on behalf of the SAEM Academic Emergency Medicine Pharmacists Interest Group
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Diabetic ketoacidosis (DKA) is a common diagnosis in the emergency department (ED) and frequently leads to prolonged hospital stays. Traditional DKA management involves continuous intravenous (IV) insulin therapy, followed by initiation of subcutaneous longacting insulin (LAI) after resolution of DKA. The latest American Diabetes Association (ADA) guidelines recommend overlapping LAI with IV insulin for at least one to two hours before discontinuing the infusion to prevent rebound hyperglycemia or recurrence of DKA. Recently, there has been growing interest—and emerging evidence— supporting the earlier initiation of LAI in DKA management, even before
resolution. The traditional two-hour overlap recommendation originated during the era when neutral protamine Hagedorn (NPH) insulin, with an onset of action of about one to two hours, was the predominant long-acting agent. Newer LAIs, such as glargine and detemir, have slower onsets of action—typically up to three to four hours—and have largely replaced NPH as the preferred LAI. This shift suggests that a two-hour overlap may be insufficient. Early initiation of LAI may offer several benefits: more effective overlap with intravenous insulin, reduced rates of rebound hyperglycemia, shorter intensive care unit (ICU) and hospital stays, and faster DKA resolution.
The Joint British Diabetes Society (JBDS) guidelines support early administration of subcutaneous basal insulin. While the ADA guidelines also reference early initiation, the JBDS recommendations are more robust. JBDS guidelines suggest continuing a patient’s home long-acting insulin at the usual schedule during DKA management with IV insulin infusion. For newly diagnosed patients, they recommend initiating LAI at a dose of 0.25 units/kg subcutaneously once daily—often at the same time of IV insulin is started. Although these guidelines advocate for simultaneous use of LAI and IV insulin in DKA management, the practice is not yet