Experience with NovoPen, an injection device using cartridged insulin, for diabetic patients

The Review of Insulin Pens-Past, Present, and Look to the Future

Currently, there are about 150-200 million diabetic patients treated with insulin globally. The year 2021 is special because the 100th anniversary of the insulin discovery is being celebrated. It is a good occasion to sum up the insulin pen technology invention and improvement which are nowadays the leading mode of an insulin delivery. Even though so many years have passed, insulin is still administered subcutaneously, that is why devices to deliver it are of great importance. Insulin pens have evolved only through the last decades (the reusable, durable pens, and the disposable, prefilled pens) and modern smart insulin pens have been developed in the last few years, and both types of the devices compared to traditional syringes and vials are more convenient, discrete in use, have better dosing accuracy, and improve adherence. In this review, we will focus on the history of insulin pens and their improvement over the previous decades.

Living with Insulin: The story of insulin from people with diabetes

The history of insulin is rightly considered one of the most beautiful stories in medicine which goes even further than the extraordinary result of tens of millions of lives saved. Without a doubt, it constitutes a major achievement for medical science which, especially in the last 50 years, has led to an impressive acceleration in the succession of new treatment opportunities. We are going to describe the history of insulin therapy, the history we lived from two different angles as people living with type 1 diabetes, and obviously also as diabetologists, but as diabetologists with diabetes. Without a doubt, insulin and his story constitutes a major achievement for medical science which has led to an impressive acceleration in the succession of new treatment opportunities. Care opportunities that have not only allowed fundamental improvements in outcomes, but have also and above all impacted the quality of life of people with diabetes. Summarizing one hundred years of insulin is no simple endeavor. In our view, it would be easier, and probably more befitting, to focus on the last 50 years, namely the period we have lived closely and personally together with insulin. More to the point, these last 50 years have witnessed a dramatic acceleration of research and innovation. In our opinion, it is precisely the innovations in insulin therapy introduced from the last decades that fully justify the description of events in this incredible period as "the miracle of insulin". We'll describe how the most important innovations introduced in the last decades had impact on what we have nowadays, as patients and diabetologits: today, we can finally adapt insulin therapy to the patient's life or lifestyle, reversing what was the perception of patients until 20 years, when insulin was considered, by the most, as an obstacle, which seemed insurmountable to some, to a free and unconstrained life.

Toward a new age of patient centricity? The application of eye-tracking to the development of connected self-injection systems

BACKGROUND

Increasing interest in digitally enhanced drug delivery tools urges both industry and academia to rethink current approaches to product usability testing. This article introduces mobile eye-tracking, generating detailed contextual data about user engagement with connected self-injection systems as a new methodological approach to formative usability assessment.

METHODS

A longitudinal case study with a total of 35 injection-naïve participants was conducted. In three consecutive experiments, eye-tracking was applied to formative usability testing of a novel connected self-injection device. Three eye-tracking derived usability indicators were established to assess product effectiveness, efficiency, and ease of use.

RESULTS

Analysis of the data revealed events of user hesitation, process interruption and unintended action, and these occurrences could either be completely eliminated or significantly reduced throughout the process (product effectiveness). At the same time, the overall use duration decreased from 86.1 to 58.7 sec (product efficiency). Analysis revealed that product modifications successfully guided user attention to those interface elements most relevant during each task, thereby improving product ease-of-use.

CONCLUSIONS

The step-wise improvement in the usability indicators demonstrates that iteratively applying eye-tracking methods effectively supports the user-centered design of connected self-injection systems. The results highlight how eye-tracking can be employed to gain an in-depth understanding of patient engagement with novel healthcare technologies.

A review of 25 years' experience with the NovoPen family of insulin pens in the management of diabetes mellitus

NovoPen, the first insulin pen, was introduced in 1985. This review article is an update of a review paper published in 2006 on 20 years' use of the NovoPen family of insulin pens in the management of diabetes mellitus. The literature searches conducted in the earlier review article were updated with search results for new articles published since April 2005. This was followed by an iterative search of references cited in identified publications and by searches of abstracts from proceedings of major international diabetes conferences since 2005. Most of the original studies identified in the 2006 review showed that insulin regimens using the NovoPen family of insulin pens were at least as effective (and in some cases superior) in maintaining glycaemic control and were as safe (in terms of hypoglycaemia) as conventional insulin regimens employing vials and syringes. Most patients preferred the various NovoPen insulin pens over vials and syringes, with some evidence suggesting that the use of discreet devices, such as those of the NovoPen family, facilitates intensive insulin therapy regimens, thereby helping to improve lifestyle flexibility. The new search results showed that the current generation of the device for the adult population, NovoPen 4, retains these benefits and further meets patients' needs by improving ease of use, convenience and discretion, which may be particularly important for those with manual dexterity, visual or auditory impairments. There was also evidence that healthcare professionals would be more likely to recommend NovoPen 4 to their patients than other devices. The recently introduced NovoPen Echo, designed specifically for the paediatric population, combines half-increment dosing with a memory function that can be used to retrieve information about the time and amount of the last dose, potentially reducing the fear of double dosing or missing a dose. Evidence obtained from the new searches suggested that paediatric patients, their parents and healthcare professionals were highly satisfied with NovoPen Echo overall, with most paediatric patients rating it their favourite pen compared with other insulin pens. In conclusion, new data published over the last 5 years on the use of NovoPen devices add to the large body of published evidence supporting the patient-related benefits of durable insulin injection pens in the treatment of diabetes since the first such pen was introduced in 1985. Together, the benefits of NovoPen are considered likely to improve both patients' quality of life and their compliance with therapy.

A Review of 20??Years??? Experience with the Novopen?? Family of Insulin Injection Devices

NovoPen, the first insulin pen injector, was introduced in 1985. This article reviews the published evidence over two decades of use of the NovoPen family of injection devices in diabetes management. A search for NovoPen publications from 1985 onwards was conducted in the following databases: MEDLINE/PubMed, Cochrane Database of Systematic Reviews, American College of Physicians Journal Club, Database of Abstract Reviews and Effects, and Cochrane Controlled Trials Register. Publications were examined and underwent a selection process to identify studies of NovoPen devices (NovoPen [1], NovoPen 2, NovoPen 1.5 and NovoPen 3) in the diabetes/insulin therapy area that contained evidence of the effects of NovoPen in a variety of categories. Of the studies identified, most showed that insulin regimens using the NovoPen family of devices are at least as effective (and in some cases superior) in maintaining glycaemic control and are as safe (in terms of hypoglycaemia) as conventional insulin regimens employing syringes. The published evidence identified also showed that insulin administration via NovoPen devices was for most patients easier, more convenient and quicker than with conventional syringes and that most patients preferred the various NovoPen devices over syringes. There was also some evidence that the use of discreet devices, like those of the NovoPen family, facilitates adherence to intensive insulin therapy regimens, helps to improve lifestyle flexibility and reduces injection pain compared with conventional syringe-based regimens. Together these benefits of NovoPen devices are considered likely to improve both patients' quality of life and compliance with therapy. In conclusion, a large body of published evidence accumulated over the past two decades testifies to the patient-related benefits of the NovoPen family of insulin injection devices in the treatment of diabetes.

Effect on quality of life with a new insulin injection device in elderly patients with diabetes mellitus type 2

OBJECTIVE

The aim was to investigate the efficacy, safety, and satisfaction of a new insulin injection device in elderly subjects with type 2 diabetes on suboptimal glycemic control with two doses of insulin NPH alone.

RESEARCH DESIGN AND METHODS

This study was a prospective no-blind study performed. We selected 25 patients (13 men and 12 women) with type 2 diabetes, only treated with two doses of NPH insulin (injection pen device) for more than 6 months, who did not achieved optimal glycemic control. Additional inclusion criterion was age 55 to 75 years (mean 65.6+/-8.6). All subjects were required to be able to comply with the protocol and carry out home blood glucose monitoring.

RESULTS

HbA1c decreased significantly from 7.8% to 7.6% (P<.05) (2.6% decreased from baseline), and breakfast and lunch preprandial glucose controls decreased significantly. Significant decrease was detected in breakfast and dinner postprandial glucose level. Taken the patients as a whole, insulin dose change significantly (29.8+/-10.9 to 28+/-10.8 Ul/day; P<.05). The number of hypoglycemic events during the 3-month treatment was similar than before treatment with Innolet (2.3+/-3.9 to 1.4+/-2.6 events; ns). The summary results indicated significantly improvement satisfaction questionnaire before 23.9+/-9 points and after 34.5+/-6.5 insulin injection device (P<.05).

CONCLUSION

Innolet improved glycemic control and satisfaction in a group of elderly patients with diabetes mellitus type 2 previously treated with pen devices.

Intestinal absorption of human insulin in pigs using delivery systems based on superporous hydrogel polymers

In this in vivo study, novel delivery systems based on superporous hydrogel (SPH) and SPH composite (SPHC) polymers were used to improve the intestinal absorption of insulin in healthy pigs. Six female pigs of approximately 35 kg body weight were used. A cannula was inserted into the jugular vein for blood sampling and a silicone fistula in the duodenum for administration of gelatin capsules containing the delivery systems or insulin solutions. The delivery systems consisted of two components, (1) conveyor system made of SPH and SPHC; (2) core containing insulin. The core was inserted either into the conveyor system (core inside, c.i.) or attached to the surface of conveyor system (core outside, c.o.). The following intestinal formulations were investigated: c.i., c.o. and intraduodenal (i.d.) administration of insulin solutions. Subcutaneous (s.c.) injection of insulin was also investigated for reasons of comparison. Blood samples were taken and analyzed for insulin and glucose concentrations. Relative bioavalibility values of 1.3+/-0.4 and 1.9+/-0.7% were achieved for c.o. and c.i. administrations, respectively. The bioavalibility for i.d. administration of insulin solution was 0.5+/-0.2%. These results indicate that the absorption of insulin was slightly increased using SPH/SPHC-based delivery systems. Furthermore, a large variability was observed, probably due to physiological and metabolic changes during the experiments. Blood glucose levels were slightly decreased after the c.o. and c.i administrations, whereas these levels did not decrease after i.d. administration of insulin solutions. In conclusion, SPH/SPHC-based delivery systems are able to enhance the intestinal absorption of insulin and are, therefore, considered as promising systems for peroral peptide drug delivery. However, insulin delivery from these delivery systems under in vivo have to be improved.

Accuracy and Precision of the Novopen® 3 Insulin Delivery Device after Mechanical and Temperature Stresses

OBJECTIVE

To evaluate the precision, accuracy, and durability of an insulin pen injection device (NovoPen 3) at three preset doses (2 IU, 35 IU, and 70 IU) after exposure to various stress and durability tests that were intended to simulate daily use by patients.

METHODS

Twenty-nine reusable NovoPen 3 insulin delivery devices were tested. The precision and accuracy of 10 insulin pen devices were evaluated after they were subjected to multiple thermal and vibration stress tests. Another 10 pen devices were subjected to a free-fall test. Nine other insulin pens were subjected to endurance testing that simulated 5 years of injections.

RESULTS

The accuracy (as measured by the relative error of the delivered dose of insulin) of the insulin pen injection devices was within 1% of the preset dose after all stress or endurance tests. A free-fall test produced no indication of damage except for broken clips and snap catches on the caps, which did not affect the integrity or performance of the insulin pens. The precision of the pen devices (as measured by relative standard deviations of delivered volumes of insulin) was likewise high after thermal stress, vibration stress, free-fall testing, or 5-year endurance testing.

CONCLUSION

Overall, this study showed that the insulin pen injection devices tested were durable under conditions of stress likely to be encountered in daily patient use. Neither a wide variety of repetitive stresses nor insulin injection cycles corresponding to 5 years of use affected the accuracy or precision enough to have clinical significance for reliable insulin delivery.

Acceptability of a reusable insulin pen, HumaPen Ergo, by patients with type 1 and type 2 diabetes

A reusable insulin pen (HumaPen Ergo) was tested for patient acceptability and safety in two multinational studies involving a total of 230 patients with either type 1 (27%) or type 2 (73%) diabetes. Prior to the studies, all patients used other insulin injection pen models. During the 5-7-week studies, the acceptability of HumaPen Ergo was assessed with a questionnaire which was issued to all patients. The HumaPen Ergo was considered easy/very easy with respect to learning to use (97%), reading dose numbers (95%) and correcting dose mistakes (97%), and 62% considered it easy/very easy to hold during use. HumaPen Ergo features considered easier/much easier compared to the previously used model of pen were ease of correcting dose (Study 1/Study 2: 89%/93%), ease of reading the dose number (77%/61 %) and ease of changing cartridge (54%/68%). At the end of the studies the majority of patients (60%/69%) said that they would continue to use HumaPen Ergo and would recommend it to other patients, even though they had expressed satisfaction with the pen that they had used previously. Health-care professionals evaluated HumaPen Ergo according to the same criteria as the patients and said that they would recommend the HumaPen Ergo owing to ease of dialling back without wasting insulin (80%) and reading dose numbers (74%). The HumaPen Ergo was well accepted by both patients and health-care professionals and provides an important tool to combat the trauma and inconvenience associated with insulin self-injection.

Type 1 diabetes mellitus in a routine diabetes clinic: the association of psycho-social factors, diabetes knowledge and glycaemic control to insulin regime

In controlled trials intensified diabetes therapy including multiple insulin injection regimes has been shown to improve glycaemic and microvascular disease outcomes in insulin dependent diabetes but this is not clear in routine outpatient practice. We undertook a pragmatic cross sectional study of 200 patients with Type 1 diabetes aged 18-50 years. There were 108 on two insulin injections/day (conventional) and 92 on four injections/day (multiple) with no significant difference for age, sex, social class, body mass index, diabetes duration, hypoglycaemia rate or complications prevalence. The relationship of insulin injection regime used with diabetes knowledge, psychological factors and glycaemic control outcomes was evaluated. Percent glycated HbA1c concentrations (normal range < 5.5%) were worse in the multiple injection group (7.5 +/- 1.7 vs. 6.8 +/- 1.4%, P < 0.001) (mean +/- SD). Their scores for diabetes knowledge (72.5 +/- 8.2 vs. 69.0 +/- 9.8, P < 0.01) were better but treatment satisfaction (29.9 +/- 5.1 vs. 28.5 +/- 6.1, ns) and well-being (49.1 +/- 10.7 vs. 46.5 +/- 12.7, ns) scores were not. Parameters of perceived locus of control were (multiple v conventional): personal (self), 24.5 +/- 5.0 vs. 22.3 +/- 5.9, P < 0.05; medical (doctor), 11.8 +/- 5.1 vs. 10.8 +/- 5.8, ns; situational (chance), 7.9 +/- 5.1 vs. 8.9 +/- 5.9, ns. In multiple regression of HbA1c versus multiple variables only insulin regime (P < 0.001) was significant. We conclude that in routine clinical practice the use of intensive insulin regimes are associated with worse glycaemic control despite patients being marginally more knowledgeable and self directed.

Audit of the change from twice daily to basal-bolus insulin regimens in insulin-dependent diabetes

Basal-bolus insulin regimens have become popular with patients, but clinicians' enthusiasm for their use has been tempered by a number of reports that suggest that these regimens do not improve overall glycemic control when compared with conventional, twice daily, regimens. Indeed, it has been suggested that basal-bolus regimens may be abused by certain patients leading to an increase in body weight and deterioration in glycemic control. This paper reports the results of a retrospective audit of 145 insulin-dependent diabetic patients changed from conventional insulin therapy to a basal-bolus insulin regimen. After 3 months on the basal-bolus regimen, a small but significant fall in total insulin (10%; p < 0.001) and intermediate-acting insulin (50%; p < 0.001) dose was recorded. During this time period serum fructosamine measurements also fell by 10% (p < 0.001) indicating a small but significant improvement in glycemic control. Body-mass index (BMI) and body weight data did not support the view that basal-bolus regimens lead to an increase in body weight. Analysis of the data by gender did not support the view that the basal-bolus insulin regimen is prone to abuse by female patients.

Audit of multiple insulin injection regimens in a large outpatient diabetic population

One hundred out-patients treated by multiple insulin injection regimens underwent clinical audit by retrospective analysis of their case-notes. Patients had been on multiple insulin injection therapy (MIIT) for 1.0-4.5 years (median, 3.6 years) and had had diabetes for 2 months-33 years (median, 8.7 years) at the time of starting pen therapy. Median daily insulin dose per patient did not differ significantly following stabilisation on MIIT or at latest follow-up. The median glycated haemoglobin did not change during each of the 4 years of follow-up. During the year prior to commencing MIIT the patients showed no significant alteration in body weight. Patients' weights rose significantly during each subsequent year. Median weight gains were 0.9 kg (P less than 0.005) during the first year, 1.4 kg (P less than 0.005) during the second year, 0.9 kg (P less than 0.05) during the third year and 1.4 kg (P less than 0.05) during year 4. No such weight gain was recorded in a control group of 30 patients matched for age and duration of diabetes and treated by twice daily insulin injections. Multiple insulin injection regimens used over prolonged periods in a routine clinic setting do not alter metabolic control. However, continuing weight gain appears to occur despite similar daily insulin doses.

Does flexibility at mealtimes disturb blood glucose control on a multiple insulin injection regimen?

Randomized crossover studies of a half-sized lunch with reduced insulin dose in 21 patients, and a delayed (by 2 h) evening meal in 22 patients, compared with normal meals, were performed in Type 1 diabetic patients. The aim was to examine whether the size and timing of meals can be varied in patients on multiple injection regimens without disturbance of blood glucose control. All patients had previously had their control optimized on multiple injection therapy using a pen-injector. The studies were carried out at home on 6 days (3 changed meals, 3 control) over 2 months, and as 8- and 7-h metabolic profiles (1 study day, 1 control) in an investigation unit. A halved calorie lunch with half the usual insulin dose resulted in equivalent blood glucose control on the study day (area under curve: changed meal 40.0 +/- 3.4 vs control meal 40.3 +/- 3.5 mmol l-1 h for the 5-h period after the meal). Ketone body levels were also unchanged. The late evening meal shifted the post-prandial blood glucose concentration accordingly, but the excursion was not different in extent from the control day (24.8 +/- 1.9 vs 21.0 +/- 1.7 mmol l-1 h). A small excursion of 3-hydroxybutyrate levels before the delayed meal (to 187 +/- 48 mumol l-1) was quickly corrected on eating. Hypoglycaemia was not different in frequency on the changed meal days. Thus no problems of clinical significance were observed when some flexibility in meal size and timing was allowed.

Long term efficacy of a pen injector

We assessed the long term efficacy of Novopen as a form of insulin administration. Records were obtained on 48 patients who were treated with Novopen between January '86 and October '88. Six patients were excluded due to insufficient data. The study group of 42 patients comprised 22 females and 20 males of average age 33 years (range 17-66). Mean Hb.A1 rose from 10.6% to 12.1% after Novopen therapy, a rise of 14.1%. This rise is both clinically and statistically significant (p less than 0.001; 99% confidence limits 0.59-2.78). Increases in weight and insulin dose were also noted, but did not reach statistical significance. The majority of patients felt Novopen was superior to twice daily insulin in terms of ease of administration (81%) and flexibility of lifestyle (95%), and all who were using Novopen wished to continue with it. More than 50% of patients admitted to altering their dietary habits while using Novopen. Despite continuing patient satisfaction with this form of insulin administration, its long-term use may be associated with sub-optimal metabolic control.

Insulin-pen treatment, quality of life and metabolic control: retrospective intra-group evaluations

The significance of the insulin pen for the quality of life of patients with insulin-dependent diabetes mellitus (IDDM) has been debated. The aim of this study was to empirically investigate whether quality of life and metabolic control improve and whether insulin requirements change subsequent to multiple injection-pen treatment. The study group comprised 72 consecutive outpatients with IDDM. Thirty-eight subjects had an initial daily regimen of one or two injections, and the remaining 34 subjects had three or more injections. All patients had four or five injections per day during pen treatment. Perceived changes in quality of life attributed to pen treatment were assessed retrospectively at follow-up 9-13 months after the changeover. Data on metabolic control (HbA1c) and insulin dose were collected at base-line and follow-up. The life quality of the IDDM-patients improved consistently, a finding corroborated by recent studies with other designs and methods. Metabolic control improved only for those patients who previously had one or two injections. The insulin requirements did not change. In conclusion, the pen contributes to a better life for the IDDM patient. The quality of life changes due to treatment intervention appear to be assessable.

An assessment of the accuracy of NovoPen 1 delivery after prolonged use

Forty-five NovoPen 1 injection devices have been assessed for accuracy of insulin delivery. Twenty-six pen-injectors had been returned either because the device had developed structural faults or the patients had experienced unexpected deterioration in diabetic control. Twelve of these pen-injectors were unusable. The remaining 14 pen-injectors ('faculty pen-injectors') were assessed by measuring the weight of insulin solution delivered in each of 10 depressions of the plunger and compared with similar measurements from 10 unused pen-injectors ('new pen-injectors') and 9 pen-injectors ('used pen-injectors') which had been used uneventfully for greater than 3 years. New pen-injectors delivered insulin solution with an accuracy (median error) of 2.8% and reproducibility (median SD) of 2.0%. Used pen-injectors had an accuracy of 2.3% and reproducibility of 3.5%. The 14 suspect pen-injectors ('faculty pen-injectors') demonstrated an accuracy of 2.8% with reproducibility of 4.0%. The reduction in reproducibility was due to faults in 4 pen-injectors, 2 of which consistently delivered less insulin than expected, while a further two pen-injectors were intermittently inaccurate.

Multiple daily insulin injections improve self-confidence

The efficacy and psychosocial effects of multiple daily insulin injections (three preprandial injections of short-acting insulin (NovoPen) and once daily, bedtime extended-acting insulin) were compared with those of twice daily combinations of short- and intermediate-acting insulin, in a randomized crossover study (two 6-month periods), in 16 adult diabetic patients. HbA1 was not significantly different for the two treatment modalities (8.2 +/- 0.4 vs 7.6 +/- 0.4%). With the pen-injector regimen significantly less state anxiety (36.0 +/- 2.5 vs 39.5 +/- 2.7; p less than 0.05) was found than with the conventional syringe regimen. The patients tended to experience a better self-concept as having diabetes (32.0 +/- 2.1 vs 37.7 +/- 3.0; p less than 0.06), as well as less external ('chance') orientation (18.5 +/- 1.2 vs 20.7 +/- 1.6; p = 0.09) with the pen-injector regimen. A subgroup of patients with lower trait anxiety scores experienced less state anxiety during the pen-injector regimen than during twice daily insulin injections (30.6 +/- 2.6 vs 34.3 +/- 2.7; p less than 0.05). However, this subgroup tended to be less positive about injecting insulin during the pen-injector regimen (34.8 +/- 3.6 vs 29.6 +/- 4.0; p less than 0.08). The subgroup with higher trait anxiety scores experienced a better self-concept as having diabetes (35.3 +/- 2.3 vs 40.1 +/- 2.6; p less than 0.05) and a tendency towards less physician orientation (15.8 +/- 1.8 vs 19.6 +/- 2.7; p less than 0.07) with the pen-injector regimen. Thirteen patients continued with the pen-injector regimen.

Growth hormone administration by means of an injection pen

We have evaluated the pharmacokinetics, reliability and patient tolerability of a newly developed injection pen for cartridged growth hormone (GH). The cartridge contains 25 IU GH in 2 ml solvents. The pen, which is basically a needle, syringe and vial in one piece, is operated by a turning movement and allows doses from 0.25-4 IU. Nine GH deficient patients were hospitalized twice for overnight bloodsampling following subcutaneous injections (at 8 p.m.) of GH: i.e. when using traditional syringe and vial and after 6 weeks of use of the pen. Serum GH antibodies were measured immediately prior to, and 3 and 6 months following pen treatment. GH containers were collected regularly from the patients for chemical analysis. A questionnaire was completed during and at the end of the study. The absorption rate and bioavailability of GH tended to be higher with syringe and vial (2 P = 0.07) but there were no differences in the profiles of IGF-I, insulin, glucagon or pertinent metabolic parameters following the 2 injection modes. No GH antibodies occurred during 6 months of pen treatment. The content of polymeric GH was lower in the cartridges (2 P less than 0.001). Seven of the patients reported less injection pain when using the injection pen, which they all strongly preferred and wished to continue using. We conclude that the GH injection pen is a reliable tool which seems to be more convenient for the patients.

Efficacy and acceptance of two intensified conventional insulin therapy regimens: a long-term cross-over comparison

The efficacy and acceptability of multiple daily insulin injections (three preprandial injections of short-acting insulin (NovoPen) plus once daily extended-acting insulin) were compared with those of twice daily injections of short- and intermediate-acting insulin. Sixteen Type 1 diabetic patients participated in a cross-over study (6-month treatment periods). Total areas under 24-h plasma free insulin curves, assessed at the end of each study period, were not significantly different, but a greater area under this curve was found for the pen-injector regimen from 1200 to 1600 h (150 +/- 15 (SE) vs 106 +/- 7 mU l-1 h, p less than 0.01). Home blood glucose profiles showed significantly lower values with pen-injector therapy after lunch (7.1 +/- 0.6 vs 8.4 +/- 0.4 mmol l-1, p = 0.05) and before and after dinner (6.4 +/- 0.6 vs 8.8 +/- 0.5 mmol l-1, p less than 0.005, and 7.5 +/- 0.7 vs 9.4 +/- 1.1 mmol l-1, p less than 0.05). Mean daily blood glucose concentration was also lower (7.1 +/- 0.4 vs 8.2 +/- 0.5 mmol l-1, p less than 0.05). HbA1, fructosamine, hypoglycaemic reactions, and body weight were not significantly different. Thirteen patients decided to continue with pen-injector therapy at the end of the study.

The use of multiple insulin injection therapy using 'NovoPen' in a routine out-patient setting

Multiple injection therapy using self-contained cartridge devices such as NovoPen has become a standard option for the treatment of insulin-requiring diabetes in recent years. Such treatment was previously viewed as impractical by the majority of patients and their physicians. Many small pilot studies have suggested that the use of such therapy leads to improvements in glycaemic control. We have many (greater than 200) patients in our clinic who use this form of treatment in the context of a routine out-patient department, where intensive supervision, which characterises all studies involving small numbers, is not practical. We have carried out a questionnaire survey of these patients to ascertain their attitudes to this form of therapy, and made some assessment of its impact on glycaemic control. Multiple injection therapy is a very popular form of therapy, leading to improvements in lifestyle and reduction in frequency of hypoglycaemic symptoms. However, its lack of impact on glycaemic control as estimated by measurement of haemoglobin A1 is disappointing.

The influence of different insulin regimens on quality of life and metabolic control in insulin-dependent diabetics

Administration of insulin with premeal boluses of short-acting insulin using a new injection device (Novopen) was compared with a conventional three times daily injection regimen regarding aspects of quality of life and metabolic control in insulin-dependent diabetes mellitus (IDDM). Eighteen C-peptide-negative patients with IDDM (16 men, two women, aged 31.0 +/- 7.4 years, duration of diabetes 13.0 +/- 4.6 years; mean +/- SD) participated in the study. All patients had been treated with three daily insulin injections for at least 1 year prior to the study. The patients were randomized into two groups. Group A started a 3-month treatment period with premeal injections of short-acting insulin and intermediate-acting insulin at bedtime. This period was followed by another 3 months using the initial three times daily injection regimen. Group B completed the study in the reverse order. Quality of life was assessed by using questionnaires and personal interviews by the same clinical psychologist. Metabolic control was assessed by measuring the levels of glycosylated hemoglobin. The results show that both treatment groups experienced a general improvement in mood and well-being during the period with multiple insulin injection treatment. Furthermore, during the periods of insulin pen treatment, an increased experience of freedom and less dependence on fixed meal times were noted. Overall metabolic control, insulin dosage, body weight, and number of hypoglycemic episodes did not change during the study. It is concluded that metabolic control, safety, and number of hypoglycemic episodes using premeal doses of short-acting insulin using Novopen were not different from those seen during conventional treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

A randomized trial of the efficacy and acceptability of a pen injector

A controlled trial of pen injection of insulin was performed in 78 patients, with assessment of metabolic control and lifestyle. After a 6-week run-in period, during which control was optimized, the patients were randomized, either to stay on a twice daily insulin regimen (n = 37), or to change to a three times daily pen regimen with human ultralente at night (n = 41). Over the 20 weeks, there was no significant change in mean glycosylated haemoglobin (syringe, mean +/- SD, 11.1 +/- 2.5% to 10.9 +/- 2.0%; pen, 11.3 +/- 2.6% to 11.2 +/- 2.0%), in blood glucose profiles or in frequency of hypoglycaemic attacks in either group. A self-completed questionnaire demonstrated high patient satisfaction with the pen injector (NovoPen), 78% for effect on lifestyle and 81% for increased flexibility. Ninety-five percent preferred the pen injector regimen to conventional treatment and stayed on it.

Improvement in morning hyperglycaemia with basal human ultratard and prandial human actrapid insulin--a comparison of multiple injection regimens

Three 'pen'-administered multiple injection regimens have been compared with twice daily insulin injection regimens by means of 24-h profiles of plasma glucose and free insulin concentrations. Ten Type 1 diabetic patients received their usual twice daily insulin regimen and were then randomized to receive the same total daily insulin dose in four divided doses using (1) 50:50 premixed soluble and isophane, (2) 30:70 premixed soluble and isophane, and (3) preprandial soluble and evening crystalline-zinc insulins. Profiles were performed after 1 week on each regimen. Plasma glucose concentrations were similar during the twice daily regimen and the two premixed regimens, rising during the early hours of the morning to a peak between 0900 and 0930 h of 13.8 +/- 2.8 (+/- SD) mmol l-1 on the twice daily regimen, 13.6 +/- 5.3 mmol l-1 on the premixed 50:50 regimen, and 13.5 +/- 4.2 mmol-1 on the premixed 30:70 regimen. With the basal and prandial regimen, overnight plasma glucose concentrations were higher than with the other regimens between 2400 and 0300 h (p less than 0.05). Concentrations then fell until breakfast, and rose after this meal to a peak of 9.5 +/- 4.3 mmol l-1 (p less than 0.01). Mean plasma glucose concentrations were significantly lower than on the other three regimens between 0830 and 1100 h (p less than 0.05). Less variability was observed in 24-h mean plasma glucose concentrations during the basal and prandial regimen than during the other three regimens.

An indwelling subcutaneous FEP cannula for intermittent insulin injection: patient experience and effect on diabetic control

The acceptability and efficacy of injecting insulin through a subcutaneous FEP cannula (to reduce the frequency of needle pricks) compared with conventional multiple injection therapy was examined in a cross-over study. Thirty-two insulin-dependent diabetic patients injected through the cannula for 10 weeks using a pen injector, followed by 10 weeks using the injector alone, or vice versa. Rapid-acting insulin was given before meals and intermediate-acting insulin at bedtime. Blood glucose control was not affected by cannula use (glycosylated haemoglobin: cannula, 8.6 +/- 0.3%; no cannula, 8.6 +/- 0.3%). Twenty-two of the 30 patients completing the study preferred to use the cannula and 21 requested to continue using it. There were no complications associated with its use.

NPH insulin administration by means of a pen injector

In an open randomized cross-over study 50 patients with insulin-dependent diabetes were allocated to 3 months of treatment with NPH insulin either by means of a pen injector (Insuject-X) or by conventional syringes. The needle of the NPH pen injector was removed immediately after use to avoid possible leakage of solvent. Ambulatory control was assessed every 6 weeks, including blood sampling (HbA1c and insulin antibodies) and recording of hypoglycaemia. NPH insulin containers were collected for insulin potency measurement by HPLC. A seven-point blood glucose profile was performed fortnightly by means of home blood glucose monitoring. At the end of the 6 months a questionnaire was completed. No significant changes occurred in HbA1c (difference 0.1 +/- 0.7 (SD)%), blood glucose profile, or the incidence of hypoglycaemic episodes on the two regimens. The concentration of NPH insulin in the containers remained constant. All but two of the patients preferred to continue to use the pen injector. This NPH pen injector is a reliable and efficacious tool which may also prove more convenient for the patients.

A comparison of morning and bed-time ultralente administration when using multiple injections in adolescence

Ten adolescents took part in a randomized sequential crossover study comparing two insulin regimes: (1) three preprandial injections of soluble insulin from a pen injector plus ultralente given before bed; (2) morning soluble insulin with ultralente, plus two preprandial injections of soluble. Nine patients completed the study. Metabolic profiles were performed at the end of each 3-month treatment period. Glycosylated haemoglobin levels did not fall significantly on either regimen, and there were no differences between the changes in HbA1 concentration on the two regimens. However, blood glucose concentrations tended to be lower with bedtime than with morning ultralente, and were significantly different at 0800 h (13.1 +/- 2.3 mmol/l vs 17.9 +/- 1.9 mmol/l, p less than 0.02) and 1000 h (14.5 +/- 1.4 mmol/l vs 18.6 +/- 0.7 mmol/l, p less than 0.03). Plasma free insulin concentrations were not different. Total daily insulin dose and the proportion of ultralente given in each regimen did not differ. Results indicate that the rise in early morning fasting blood glucose concentrations was less when ultralente was given at bedtime rather than in the morning.

Improved diabetic control in adolescents using the Penject syringe for multiple insulin injections

Eleven adolescent diabetics, aged 15.1 +/- 1.3 years (mean +/- 1SD) in poor glycaemic control (HbA1 12.0 +/- 1.5% at entry) were commenced on a four times daily insulin injection regimen using the Penject fountain-pen syringe with Initard (50:50 mixture of porcine soluble and isophane) insulin on a sliding scale. Diabetic control improved over a 3-month period, assessed by a reduction in both the mean preprandial blood glucose concentrations (10.9 +/- 3.3 mmol/l to 7.7 +/- 2.3 mmol/l) and mean glycosylated haemoglobin concentrations (12.0 +/- 1.5% to 9.5 +/- 0.9%). Further improvement was again seen in 5 patients who remained on four daily injections for an additional 3 months (mean HbA1: 9.6 +/- 0.9% to 8.4 +/- 1.0%), whereas diabetic control in 6 patients who returned to twice daily injections deteriorated (mean HbA1 rose from 9.5 +/- 1.0% to 10.6 +/- 1.6%). Multiple insulin injections using an injection pen are acceptable to adolescent diabetics and improve their control.