Properties of pramlintide and insulin upon mixing.

PURPOSE: The pharmacokinetics, pharmacodynamics, and safety of pramlintide and various insulin formulations in patients with type 1 diabetes mellitus (DM) when given as separate injections or mixed in the same syringe before injection were studied.

METHODS: In two randomized, open-label, placebo-controlled, five-period-crossover studies, patients with type 1 DM received preprandial injections of pramlintide, short-acting insulin, and long-acting insulin administered either by separate injections or after mixing in various combinations. Serum free insulin and plasma glucose concentrations were measured for 10 hours and plasma pramlintide concentrations for 5 hours after injection.

RESULTS: Blood samples were collected from a total of 51 patients. All treatments involving mixtures were comparable to separate injections with respect to the area under the concentration-versus-time curve (AUC) and the maximum concentration (Cmax) of serum free insulin. There were some minor differences in the AUC and Cmax of pramlintide. No injection-site reactions or other unexpected adverse events were observed.

CONCLUSION: Mixing pramlintide with short- or long-acting insulin in the same syringe before subcutaneous injection did not affect the pharmacodynamics of glucose or the pharmacokinetics of insulin or pramlintide in a clinically significant manner.