[Comparison of insulin loss in treatment of diabetics using the classical syringe or the insulin pen (Novopen II)].

The aim of the study was to investigate changes in insulin wastage when transferring patients from vial insulin to Actraphane HM Penfills and NovoPen II. Twenty four diabetic patients, were treated with Actraphane HM 40 IU/ml vial for 3 months, then transferred to Actraphane HM Penfill and NovoPen II for further 3 months. Wastage 1 (difference between insulin consumption and the total prescribed dose) was higher in vials than in Penfills (268.7 +/- 69.4 IU/3 months/patients vs. -7.6 +/- 30.2 IU/3 months/patient, p < 0.001 mean +/- SEM). Wastage 2 (insulin remaining in the container when discharged) was higher in the Penfills than in vials (214.1 +/- 22.04 IU/3 months/patient vs 45.2 +/- 11.2 IU/3 months/patient). Total wastage was 313.9 +/- 67.8 IU/3 months/patient (3.96 IU/day/patient) when using vials and 206.5 +/- 31.2 IU/3 months/patient (2.52 IU/day/patient) when using Penfills (NS). Higher wastage in vials may relate to a larger volume used for "airshot", and to a larger imprecision in the measured and injected dose when using vials. The latter may also be reflected in a significantly higher average incidence of weighted hypogiycemias in the vial period (15 +/- 4.28/3 months/patient) compared to the Penfill period (5.1 +/- 1.2/3 months/patient, p < 0.01). Total wastage was seen to be 29% smaller by using NovoPen II and therefore saving of insulin seems to be possible (approximately 1.44 IU/day/patient).