The impact of new insights and revised practice guidelines on prescribing drugs in the treatment of Type 2 diabetes mellitus

The effect of guideline revisions on vascular complications of type 2 diabetes

BACKGROUND

The aim of this study was to investigate the impact of implementation and revision of the 'Diabetes Mellitus type II' guideline by the Dutch College of General Practitioners (DCGP) on the prevalence and incidence of macrovascular and microvascular complications.

METHODS

The DiaGene study is a case-control study (n = 1886 patients of type 2 diabetes) with extensive, retrospectively collected complication data, as well as prospective follow up of complications. The study incorporates all lines of diabetes care. Cases were divided into categories according to the date of onset of diabetes and publication dates of the DCGP. Logistic regression models were used to investigate the associations between guideline version and complications. To investigate a possible trend between guideline version and complications, the 'guideline category' was also used as a continuous variable. All models were adjusted for clinical covariables.

RESULTS

The 1999 and 2006 guidelines versions were associated with significantly lower risk of retinopathy than the group that started without a guideline [OR 0.32 (95% CI 0.14-0.72, p = 0.006) and 0.31 (95% CI 0.11-0.91, p = 0.034), respectively]. A significant trend in reduction of peripheral artery disease (PAD) over the guideline versions was found, adjusted for age, sex and diabetes duration (odds ratio (OR) 0.70, 95% CI 0.51-0.97, p trend = 0.029) and for retinopathy in all models (OR = 0.52, 95% CI 0.37-0.73, p trend < 0.001).

CONCLUSIONS

The introduction of the first diabetes guideline and subsequent revisions have reduced the risk of macrovascular and microvascular complications of type 2 diabetes, most strongly in diabetic retinopathy. This indicates that real-time diabetes care has improved over time.

Recent trends in the use of antidiabetic medications from 2008 to 2013: A nation-wide population-based study from Taiwan

BACKGROUND

Studies from other countries indicate that utilization patterns of antidiabetic drugs change significantly after the introduction of newer classes of antidiabetic drugs (e.g. dipeptidyl peptidase-4 inhibitors [DPP-4i]). Evidence on recent trends regarding antidiabetic drug use in Taiwan is lacking, especially for times after the introduction of newer classes of drugs (e.g. DPP-4i). Therefore, the aim of the present study was to assess: (i) recent trends in the use and spending on antidiabetic drugs; (ii) changes in utilization patterns after introduction of newer classes of antidiabetic drugs; and (iii) factors associated with the choice of newer versus older classes of antidiabetic drugs.

METHODS

Cases of type 2 diabetes were derived from Taiwan's National Health Insurance Research Database. Antidiabetic drug use was measured in terms of total quantity of drug exposure and healthcare spending in each calendar year from 2008 to 2103. Multiple logistic regression analysis was used to assess factors associated with drug choice.

RESULTS

The use of and healthcare spending on DPP-4i increased significantly from 2008 to 2013, whereas healthcare spending on sulfonylureas decreased. For monotherapy, sulfonylureas were the most common alternatives to metformin, whereas in dual and triple antidiabetic therapies, a DPP-4i was the most common alternative to initial regimens. The use of a DPP-4i was positively associated with the use of beta-blockers, angiotensin II-converting enzyme inhibitors and/or angiotensin receptor blockers, and lipid-lowering agents, but negatively correlated with age, hypertension, severity of diabetes complications, and the use of diuretics and calcium channel blockers.

CONCLUSIONS

With growing spending on newer antidiabetic drugs, future research on the comparative cost-effectiveness and safety of antidiabetic drugs is anticipated.

Patterns of glucose lowering drugs utilization in Portugal and in the Netherlands. Trends over time

AIMS

To compare the temporal trends in the consumption patterns of glucose lowering drugs (GLD) between Portugal and the Netherlands from 2004 to 2013 and to examine possible reasons behind the cross-national variation found.

METHODS

All GLD (ATC pharmacological subgroup A10B) were selected for analysis. Consumption data were obtained for the 10-year period. Portuguese and Dutch drug estimates were obtained from nationwide databases.

RESULTS

The consumption of GLD increased in Portugal from 52.9 defined daily dose per 1000 inhabitants per day (DHD) in 2004 to 70.0 DHD in 2013 and in the Netherlands from 44.9 DHD in 2004 to 50.7 DHD in 2013. In Portugal, the use of fixed-dose combinations, especially with dipeptidyl peptidase-4 inhibitors (DPP-4) increased remarkably and in 2013 represented almost a quarter of total GLD consumption. In the Netherlands, the use of combinations was residual.

CONCLUSIONS

The consumption of GLD rose over the 10-year period in both countries. However, Portuguese overall consumption and costs of GLD were higher. The differentially rapid uptake of DPP-4 inhibitors in Portugal was the main driver of the cost difference.

Trends in the prescription of antidiabetic medications from 2009 to 2012 in a general practice of Southern Italy: a population-based study

OBJECTIVE

To assess the prescribing pattern of antidiabetic drugs (AD) in a general practice of Southern Italy from 2009 to 2012, with focus on behaviour prescribing changes.

METHODS

This retrospective, drug utilization study was conducted using administrative databases of the Local Health Unit of Caserta (Southern Italy) including about 1 million citizens. The standardized prevalence of AD use was calculated within each study year. A sample cohort of 78,789 subjects with at least one prescription of AD was identified during the study period.

RESULTS

There was an overall increase of the proportion of the patients treated with monotherapy, which was significant for insulin monotherapy (from 11.2 to 14.6%, p<0.001). The proportion of patients treated with metformin remained stable (from 68.3% to 67.8%, p=0.076), while those receiving sulfonylurea dropped from 18.4% to 12.5% (p<0.001); GLP-1 analogues and DPP-4 inhibitors showed the greatest increase (from 1.2% to 6.6%, p<0.001). In the whole sample of 25,148 new AD users, metformin was the most commonly prescribed drug in monotherapy (41.9%), while insulin ranked second (13.3%).

CONCLUSION

This study shows a rising trend of AD monotherapy, with sulfonylureas and incretins showing the more negative and positive trend, respectively.

Is it time to test biguanide metformin in the treatment of melanoma?

Metformin is the most widely used antidiabetic drug that belongs to the biguanide class. It is very well tolerated and has the major clinical advantage of not inducing hypoglycemia. Metformin decreases hepatic glucose production via a mechanism requiring liver kinase B1, which controls the metabolic checkpoint, AMP-activated protein kinase-mammalian target of rapamycin and neoglucogenic genes. The effects of metformin on this pathway results in reduced protein synthesis and cell proliferation. These observations have given the impetus for many investigations on the role of metformin in the regulation of tumor cell proliferation, cell-cycle regulation, apoptosis, and autophagy. Encouraging results from these studies have shown that metformin could potentially be used as an efficient anticancer drug in various neoplasms such as prostate, breast, lung, pancreas cancers, and melanoma. These findings are strengthened by retrospective epidemiological studies that have found a decrease in cancer risk in diabetic patients treated with metformin. In this review, we have focused our discussion on recent molecular mechanisms of metformin that have been described in various solid tumors in general and in melanoma in particular.

Using spatial analysis to predict health care use at the local level: a case study of type 2 diabetes medication use and its association with demographic change and socioeconomic status

Local health status and health care use may be negatively influenced by low local socio-economic profile, population decline and population ageing. To support the need for targeted local health care, we explored spatial patterns of type 2 diabetes mellitus (T2DM) drug use at local level and determined its association with local demographic, socio-economic and access to care variables. We assessed spatial variability in these associations. We estimated the five-year prevalence of T2DM drug use (2005-2009) in persons aged 45 years and older at four-digit postal code level using the University of Groningen pharmacy database IADB.nl. Statistics Netherlands supplied data on potential predictor variables. We assessed spatial clustering, correlations and estimated a multiple linear regression model and a geographically weighted regression (GWR) model. Prevalence of T2DM medicine use ranged from 2.0% to 25.4%. The regression model included the extent of population ageing, proportion of social welfare/benefits, proportion of low incomes and proportion of pensioners, all significant positive predictors of local T2DM drug use. The GWR model demonstrated considerable spatial variability in the association between T2DM drug use and above predictors and was more accurate. The findings demonstrate the added value of spatial analysis in predicting health care use at local level.

Clinical guidelines in the European Union: mapping the regulatory basis, development, quality control, implementation and evaluation across member states

INTRODUCTION

Clinical guidelines are advocated to improve the quality of care, especially for chronic diseases. However, the regulatory basis of clinical guidelines, their development, quality control, implementation and use as well as evaluation within countries across the European Union is not systematically known.

METHODS

Using information collected from key informants in each country by means of a structured questionnaire, this mapping exercise illustrates the varied status of guideline production in European Union countries.

RESULTS

Most European Union countries have an established national, regional or local clinical guideline programme, and a substantial proportion have developed guidelines on the prevention and management of chronic diseases. Several countries have mechanisms in place to ensure the quality of scientific evidence used for the development of guidelines is high and that the process is consistent and transparent. Others are only now taking an interest in guideline development and are taking the first steps towards establishing ways of implementing them. The majority of countries have no legal basis for the development of guidelines and those that have well established systems mostly implement them on a voluntary basis. The process of guideline development varies in its degrees of decentralisation across countries with many different types of organisations taking on this responsibility. There is general acceptance of the value of the instrument developed by the AGREE collaboration for evaluating the methodological robustness of guidelines. However, the extent to which guidelines are implemented in Europe is unknown, as there is no systematic data collection and, in most countries, no structure to enable it. There are few examples of formal evaluations of the development, quality, implementation and use of guidelines.

CONCLUSIONS

Our findings call for renewed efforts to respond to the severe lack of standardized guideline terminology and accessibility as well as rigorous studies to evaluate the relationship between different ways to develop guidelines and their methodological quality, between their quality and the actual implementation and usage, and finally between implementation and health outcomes.

Proton pump inhibitors inhibit metformin uptake by organic cation transporters (OCTs)

Metformin, an oral insulin-sensitizing drug, is actively transported into cells by organic cation transporters (OCT) 1, 2, and 3 (encoded by SLC22A1, SLC22A2, or SLC22A3), which are tissue specifically expressed at significant levels in various organs such as liver, muscle, and kidney. Because metformin does not undergo hepatic metabolism, drug-drug interaction by inhibition of OCT transporters may be important. So far, comprehensive data on the interaction of proton pump inhibitors (PPIs) with OCTs are missing although PPIs are frequently used in metformin-treated patients. Using in silico modeling and computational analyses, we derived pharmacophore models indicating that PPIs (i.e. omeprazole, pantoprazole, lansoprazole, rabeprazole, and tenatoprazole) are potent OCT inhibitors. We then established stably transfected cell lines expressing the human uptake transporters OCT1, OCT2, or OCT3 and tested whether these PPIs inhibit OCT-mediated metformin uptake in vitro. All tested PPIs significantly inhibited metformin uptake by OCT1, OCT2, and OCT3 in a concentration-dependent manner. Half-maximal inhibitory concentration values (IC(50)) were in the low micromolar range (3-36 µM) and thereby in the range of IC(50) values of other potent OCT drug inhibitors. Finally, we tested whether the PPIs are also transported by OCTs, but did not identify PPIs as OCT substrates. In conclusion, PPIs are potent inhibitors of the OCT-mediated metformin transport in vitro. Further studies are needed to elucidate the clinical relevance of this drug-drug interaction with potential consequences on metformin disposition and/or efficacy.

Trends in drug prescriptions to diabetic patients from 2000 to 2008 in Italy's Lombardy Region: a large population-based study

OBJECTIVE

To analyze the prescribing patterns of antidiabetic and cardiovascular medications among diabetics in the most highly populated Italian Region, from 2000 to 2008.

METHODS

Data were obtained from the Lombardy Region administrative health databases. The standardized prevalence of antidiabetic and cardiovascular drugs use was calculated within each study year. The prescription trends of initial treatment with antidiabetic drugs were also analyzed.

RESULTS

From 2000 to 2008 there was an increase in the proportion of patients treated with biguanides (from 53.4% to 66.5%; p<0.0001) while those receiving sulfonylurea decreased (from 78.6% to 56.4%; p<0.0001). A sharp increase of metformin (as monotherapy) as initial treatment was also observed (from 15.2% to 48.8%; p<0.0001). The percentage of patients receiving renin-angiotensin system inhibitors, lipid-lowering drugs and antiplatelets increased between 2000 and 2008, from respectively 45.1% to 63.3%, 13.6% to 43.2% and 21.6% to 40.9 (p<0.0001). Multivariate analyses indicated that changes in prescriptions were statistically significant for both antidiabetic and cardiovascular drugs.

CONCLUSION

This study documents progressive changes in the prescription of antidiabetic and cardiovascular drugs in accordance with guidelines. However, the use of metformin as first line therapy was still suboptimal and cardiovascular preventive strategies were only partially implemented in community practice.

Prescribing patterns and predictors of high-level polypharmacy in the elderly population: A prospective surveillance study from two teaching hospitals in India

BACKGROUND

Polypharmacy has been reported to increase the risks for inappropriate prescribing, adverse drug reactions, geriatric syndromes, and morbidity and mortality in elderly populations in the United States and Europe. Data on prescribing patterns and polypharmacy in the elderly population in India are limited.

OBJECTIVES

The aims of this study were to assess prescribing patterns and to determine the predictors of high-level polypharmacy in the elderly population in 2 tertiary care hospitals in India.

METHODS

This prospective surveillance study used medical records from patients aged 60 to 95 years admitted to the medicine wards of the 2 tertiary care hospitals between January 2008 and June 2009. Data on medication prescribing from admission through discharge were reviewed. Diseases were coded using the World Health Organization (WHO) International Classification of Diseases, 10th Revision, and medications were coded using the WHO Anatomical, Therapeutic, and Chemical classification. Concordance of prescribing with the indications in the product labeling as listed in the American Hospital Formulary Services Drug Information 2007 was determined. The prevalences of polypharmacy (5-9 medications) and high-level polypharmacy (>or=10 medications) were determined. Bivariate analysis and multivariate logistic regression analysis were used to determine the influential predictors of high-level polypharmacy during hospital stays.

RESULTS

Data from 814 patients were included (493 [60.6%] men, 321 [39.4%] women; median age, 66 years [range, 60-95 years]). Systemic antibacterials were the most commonly prescribed therapeutic class of medications (574 [70.5%]), and pantoprazole was the most commonly prescribed medication (498 [61.2%]). The majority (7/10 [70.0%]) of the most commonly prescribed medications were prescribed as indicated. Medications prescribed "off-label" included pantoprazole (432/498 [86.7%]), ceftriaxone (212/259 [81.9%]), and atorvastatin (109/237 [46.0%]). Polypharmacy and high-level polypharmacy were prescribed in 366 (45.0%) and 370 (45.5%) patients, respectively. On multivariate logistic regression analysis, multiple (>or=3) diagnoses (odds ratio [OR] = 1.55; 95% CI, 1.16-2.08; P = 0.003), angina pectoris (OR = 2.58; 95% CI, 1.50-4.37; P < 0.001), and a length of stay >or=10 days (10-<15 days, OR = 3.14; 95% CI, 2.09-4.71; P < 0.001; and >or=15 days, OR = 5.74; 95% CI, 2.43-13.51; P < 0.001) were found to be predictors of high-level polypharmacy during hospital stays.

CONCLUSIONS

The campaign for rational drug use in hospitalized elderly patients in India should promote pantoprazole, ceftriaxone, and atorvastatin prescribing in concordance with their indications. Interventions to reduce the high-level polypharmacy in the elderly during their stays in tertiary care hospitals in India should focus on patients with >/=3 diagnoses, angina pectoris, and/or >or=10 days of hospital stay.

Glibenclamide-related excess in total and cardiovascular mortality risks: data from large Ukrainian observational cohort study

OBJECTIVE

To compare mortality risks among type 2 diabetes (T2D) patients being treated with glibenclamide, gliclazide, or glimepiride.

METHODS

Retrospective observational cohort studies of primary care-based diabetes register were carried out. Risk of total and cardiovascular (CVD) mortality was evaluated in cohort of T2D patients that were treated with either glibenclamide (n=50,341), glimepiride (n=2479) or gliclazide (n=11,368). Cox regression was used for multifactor evaluation. A cross-sectional evaluation of oral anti-diabetic drug (OAD) structure for 2005 and 2007 was also performed, as well as age at the time of death was compared in the timeframe between 2002 and 2007.

RESULTS

Total mortality was lower for gliclazide and glimepiride, vs. glibenclamide cohort: HRs 0.33 (95% CI 0.26-0.41), p<0.001 and 0.605 (95% CI 0.413-0.886), p<0.01 respectively. CVD mortality risk reduction vs. glibenclamide was significant only in gliclazide cohort: 0.29 (95% CI 0.21-0.38), p<0.001. Glibenclamide prescriptions had changed from 64.0% (95% CI 63.5-64.5) to 59.5% (95% CI 9.7-10.4). Age at the time of death for OAD-treated patients increased by 6.27 (95% CI 3.67-8.87)yrs, p<0.001.

CONCLUSION

Glibenclamide treatment of T2D is associated with greater risk of all-cause mortality, vs. gliclazide or glimepiride treatment, and CVD mortality, vs. gliclazide treatment.

Assessing the appropriate use of metformin in an inpatient setting and the effectiveness of two pharmacy-based measures to improve guideline adherence

OBJECTIVE

To demonstrate the level of compliance to metformin-prescribing guidelines and to evaluate the effectiveness of 2 pharmacy-based interventions.

METHODS

Retrospective chart review of all inpatients who had received at least 2 doses of metformin while hospitalized. Two cohorts of patients had chart audits-one group (group A) hospitalized between March and August of 2003 (487 patients) and one group (group B) hospitalized between August of 2005 and January of 2006 (370 patients). In December of 2003, the pharmacy inserted a safety alert in the electronic ordering system and mailed a printed safety alert to all clinical staff outlining the contraindications and precautions concerning metformin use.

RESULTS

More than two-thirds (69.3%) of the charts reviewed demonstrated that metformin was used in accordance with the prescribing guidelines. Surgical procedures, intravenous contrast use, and elevated serum creatinine levels accounted for the greatest percentage of guideline violations. The prescribing guidelines were violated 27.4% (47/137 charts) of the times in group A and 34.3% (40/146 charts) of the times in group B.

CONCLUSIONS

The significance of this study is that metformin is often given in spite of the presence of contraindications to its use. Two pharmacy interventions were ineffective in decreasing the guideline violation frequency in a group of patients who were prescribed the drug.

Antiepileptic drug utilization in children from 1997-2005--a study from the Netherlands

OBJECTIVE

To investigate the utilization of antiepileptic drugs (AEDs) in Dutch children and compare this with guidelines on the treatment of epilepsy in children.

METHOD

From the Dutch Interaction Database (IADB.nl) we selected children aged 0-19 years who received at least one prescription for an AED (ATC-code beginning with N03A) between 1997 and 2005. We calculated cumulative incidences and prevalences per 1000 children per year, stratified by age-category, sex and type of AED, and the total number of months each patient received at least one prescription of AEDs, and we counted the number of person-months and AEDs prescribed. For each AED, proportions of person-months were calculated for mono- and combination therapy. Kaplan-Meier survival analysis was used to analyse the duration of AED use, stratified by sex.

RESULTS

The overall prevalence of the prescription of AEDs to children was constant at approximately 4.0 per 1000 children during the years of the study. The overall cumulative incidence from 1997-2005 was 0.67 per 1000 children. When stratified by age category or sex, there were no relevant differences in incidence or prevalence. Valproic acid was the most frequently prescribed drug, followed by carbamazepine and lamotrigine. In 20.3% of all person-months, patients received combination therapy; of these, 34.2% received combination therapy for 3 person-months or less. The older AEDs were prescribed more often as monotherapy than combination therapy, in contrast with the newer AEDs, for which the opposite was true. The 50% survival probability (= time period when 50% of children had stopped using AEDs) was around 2 years, with a significantly lower discontinuation of treatment for girls than boys (P = 0.04).

CONCLUSION

The overall cumulative incidence of AEDs was determined to be 0.67 per 1000 children, and the prevalence 4.0 per 1000 children. The most frequently prescribed drug is valproic acid, followed by carbamazepine and lamotrigine. The prescribing of AEDs seems to be in conformity with the overall recommendations of the guidelines on the treatment of epilepsy in children.