From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
For a patient fasting from midnight who is on a basal-bolus insulin regimen, you should administer the full dose of the long-acting (basal) insulin while withholding the fast-acting (bolus) insulin doses. This approach is supported by the most recent and highest quality study available, which emphasizes the importance of maintaining basal insulin levels during fasting periods to control background glucose production by the liver 1. The study found that when using well-titrated basal-bolus insulin therapy in hospitalized patients with type 2 diabetes, the basal insulin dose does not require adjustment during fasting periods to achieve safe glycaemic control, provided meal-related bolus insulin is omitted and correction bolus insulin is tailored to glucose levels. Key points to consider include:
- Long-acting insulins such as glargine (Lantus), detemir (Levemir), or degludec (Tresiba) should be continued at the patient's usual dose even during fasting periods.
- Reducing or omitting the basal insulin could lead to significant hyperglycemia or even diabetic ketoacidosis, especially in type 1 diabetes patients.
- Monitor the patient's blood glucose levels during the fasting period, as some patients with high insulin sensitivity or those at risk of hypoglycemia might require a modest reduction (10-20%) in basal insulin dose.
- If the patient has a history of hypoglycemia with fasting or has renal impairment, consider discussing with the diabetes team about potential dose adjustments.
- Resume the bolus insulin when the patient begins eating again, adjusting doses based on carbohydrate intake and blood glucose readings.