A multicenter, randomized, open-label, comparative, two-period crossover trial of preference, efficacy, and safety profiles of a prefilled, disposable pen and conventional vial/syringe for insulin injection in patients with type 1 or 2 diabetes mellitus.

BACKGROUND

The accuracy and convenience of pen devices for insulin injection have improved quality of life for patients with insulin-treated diabetes mellitus (DM). Prefilled, disposable pens have the advantage of simplicity, with minimal training and attention required and no installation of new cartridges necessary.

OBJECTIVE

The aim of this study was to assess patient preference, efficacy, and safety profiles of a prefilled, disposable pen (FlexPen) and conventional vial/syringe injection method for insulin injection therapy among patients with DM.

METHODS

In a multicenter, randomized, open-label, crossover study, patients with type 1 or 2 DM were transferred from previous QD or BID conventional insulin therapy to a mixture of 70% insulin aspart protamine suspension and 30% insulin aspart injection (NovoLog Mix 7030) for 4 weeks of dose optimization using their usual type of syringe. Patients were then randomly assigned to use either vial/syringe or a prefilled, disposable pen to inject the biphasic insulin aspart 7030 mixture for the next 4 weeks, followed by 4 weeks of use of the other injection device. Efficacy, safety profiles, and patient preference for the delivery systems were compared.

RESULTS

A total of 121 patients (mean [SD] age, 57.0 [12.4] years; age range, 28-81 years; mean [SD] body mass index, 31 [5.5] kg/m(2)) were enrolled. One hundred three patients completed the study. Seventy-four percent of patients (78105) indicated a preference for the pen over the vial/syringe method (95% CI, 71%-87%), compared with 20% (21105) who preferred the vial/syringe. Eighty-five percent (88104) considered the pen more discreet for use in public (compared with 9% [9104] for the vial/syringe), 74% (77104) considered it easier to use overall (compared with 21% [22104] for the vial/syringe), and 85% (89105) found the insulin dose scale on the pen easier to read (compared with 10% [10105] for the vial/syringe). Patients had statistically significant improvement in glycosylated hemoglobin values during the study (P < 0.05). No statistically significant differences in fasting plasma glucose, mean 4-point blood glucose profiles, or serum fructosamine values were found between groups. Overall, the safety profiles during treatment periods with the pen were comparable to those with the vial/syringe.

CONCLUSIONS

In this trial, differences in efficacy and safety profiles between the vial/syringe and prefilled, disposable pen appeared negligible. However, more patients expressed a preference to continue use of the pen.