Insulin Pump Therapy: Insulin Type Requirements
Yes, insulin pumps use only rapid-acting insulin analogs (such as insulin lispro, aspart, or glulisine) or, less commonly, short-acting regular insulin—never intermediate-acting or long-acting insulins. 1
Recommended Insulin Types for Pumps
Rapid-acting insulin analogs are the appropriate and preferred insulins for continuous subcutaneous insulin infusion (CSII) pumps. 1 The American Diabetes Association explicitly states that rapid-acting analogs such as insulin lispro are appropriate insulins for insulin infusion pumps, with confirmed stability in pump systems. 1
Rapid-acting analogs (lispro, aspart, glulisine) are the standard choice because their quick onset (0.25-0.5 hours), early peak (1-3 hours), and short duration (3-5 hours) allow them to mimic physiologic insulin secretion when delivered continuously. 2
Short-acting regular human insulin can be used but is less optimal—controlled trials demonstrated improved postprandial glucose control with rapid-acting analogs compared to regular insulin when delivered by CSII. 1
Why Only Short-Acting Insulins?
The pump delivers approximately 50% of total daily insulin as continuous basal infusion throughout the day and 50% as meal boluses. 3 This continuous delivery mechanism requires insulin that can be safely administered in small, frequent doses 24 hours per day. 3
Long-acting insulins (glargine, detemir, degludec) are never used in pumps because they are specifically designed for once or twice daily injection, not continuous infusion. 3
The pump itself provides the "basal" coverage through continuous delivery of rapid-acting insulin, eliminating the need for separate long-acting insulin formulations. 1
Critical Safety Consideration
Always carry backup rapid-acting insulin syringes or pens in case of pump failure. 3 Since no long-acting insulin is on board with pump therapy, pump malfunction can lead to rapid development of ketoacidosis within hours—a life-threatening emergency. 3
Undetected interruptions in insulin delivery may result in ketotic episodes more quickly with CSII compared to multiple daily injection regimens that include long-acting insulin. 1
Insulin in the pump reservoir should be replaced at least every 7 days, and infusion sets should be changed at least every 3 days to avoid insulin degradation and infusion set occlusion. 4
Mixing Insulins in Pumps
Never mix different insulins or any other liquid with the insulin in a pump reservoir. 1, 4 Use of insulin mixtures in pumps has not been evaluated and is therefore not recommended. 1
Comparative Stability Among Rapid-Acting Analogs
While all three rapid-acting analogs are approved for pump use, insulin aspart has demonstrated the greatest chemical and physical stability in insulin pumps, with the lowest rates of overall occlusion (aspart 9.2%, lispro 15.7%, glulisine 40.9%; P<0.01). 5
Clinical efficacy and glycemic control are similar among all three rapid-acting analogs when used in CSII therapy. 5
The choice among rapid-acting analogs may be based on individual patient response, insurance coverage, and pump compatibility considerations, though aspart shows superior stability data. 5