RapidActing

Rapid-acting insulins are a class of insulin analogs designed to control blood glucose during meals by mimicking the body’s normal postprandial insulin response. They are absorbed quickly after subcutaneous injection, providing a faster onset and shorter duration of action than regular human insulin. This profile helps reduce post-meal hyperglycemia and allows for more flexible timing around eating.

The main agents in this class are insulin lispro, insulin aspart, and insulin glulisine. A rapid-acting inhaled insulin product has also been marketed in various regions. All rapid-acting insulins share the goal of rapid absorption by modifying the insulin molecule to reduce hexamer formation, enabling quicker entry into the bloodstream. While their exact pharmacokinetic profiles differ slightly, typical onset occurs within 10 to 30 minutes, peak activity around 1 to 3 hours, and duration generally lasting about 3 to 5 hours, with individual variation.

Clinical use involves administering the insulin immediately before meals or just prior to eating to cover prandial glucose rises. They are commonly used as part of a basal-bolus regimen or in insulin pump therapy, allowing tighter postprandial control.

Common considerations and adverse effects include hypoglycemia, weight gain, and injection-site reactions. Lipodystrophy may occur with repeated injections at the same site. Dosing requires adjustment based on carbohydrate intake, activity, and renal or hepatic function. Storage and handling vary by product; users should follow product labeling for guidance on refrigeration, room-temperature storage, and shelf life.