Risk of sudden cardiac arrest and ventricular arrhythmia with sulfonylureas: An experience with conceptual replication in two independent populations.

Sulfonylureas are commonly used to treat type 2 diabetes mellitus. Despite awareness of their effects on cardiac physiology, a knowledge gap exists regarding their effects on cardiovascular events in real-world populations. Prior studies reported sulfonylurea-associated cardiovascular death but not serious arrhythmogenic endpoints like sudden cardiac arrest (SCA) or ventricular arrhythmia (VA). We assessed the comparative real-world risk of SCA/VA among users of second-generation sulfonylureas: glimepiride, glyburide, and glipizide. We conducted two incident user cohort studies using five-state Medicaid claims (1999-2012) and Optum Clinformatics commercial claims (2000-2016). Outcomes were SCA/VA events precipitating hospital presentation. We used Cox proportional hazards models, adjusted for high-dimensional propensity scores, to generate adjusted hazard ratios (aHR). We identified 624,406 and 491,940 sulfonylurea users, and 714 and 385 SCA/VA events, in Medicaid and Optum, respectively. Dataset-specific associations with SCA/VA for both glimepiride and glyburide (vs. glipizide) were on opposite sides of and could not exclude the null (glimepiride: aHRMedicaid 1.17, 95% CI 0.96-1.42; aHROptum 0.84, 0.65-1.08; glyburide: aHRMedicaid 0.87, 0.74-1.03; aHROptum 1.11, 0.86-1.42). Database differences in data availability, populations, and documentation completeness may have contributed to the incongruous results. Emphasis should be placed on assessing potential causes of discrepancies between conflicting studies evaluating the same research question.

Association between use of warfarin with common sulfonylureas and serious hypoglycemic events: retrospective cohort analysis.

STUDY QUESTION: Is warfarin use associated with an increased risk of serious hypoglycemic events among older people treated with the sulfonylureas glipizide and glimepiride? METHODS: This was a retrospective cohort analysis of pharmacy and medical claims from a 20% random sample of Medicare fee for service beneficiaries aged 65 years or older. It included 465,918 beneficiaries with diabetes who filled a prescription for glipizide or glimepiride between 2006 and 2011 (4,355,418 person quarters); 71,895 (15.4%) patients also filled a prescription for warfarin (416,479 person quarters with warfarin use). The main outcome measure was emergency department visit or hospital admission with a primary diagnosis of hypoglycemia in person quarters with concurrent fills of warfarin and glipizide/glimepiride compared with the rates in quarters with glipizide/glimepiride fills only, Multivariable logistic regression was used to adjust for individual characteristics. Secondary outcomes included fall related fracture and altered consciousness/mental status. SUMMARY ANSWER AND LIMITATIONS: In quarters with glipizide/glimepiride use, hospital admissions or emergency department visits for hypoglycemia were more common in person quarters with concurrent warfarin use compared with quarters without warfarin use (294/416,479 v 1903/3,938,939; adjusted odds ratio 1.22, 95% confidence interval 1.05 to 1.42). The risk of hypoglycemia associated with concurrent use was higher among people using warfarin for the first time, as well as in those aged 65-74 years. Concurrent use of warfarin and glipizide/glimepiride was also associated with hospital admission or emergency department visit for fall related fractures (3919/416,479 v 20,759/3,938,939; adjusted odds ratio 1.47, 1.41 to 1.54) and altered consciousness/mental status (2490/416,479 v 14,414/3,938,939; adjusted odds ratio 1.22, 1.16 to 1.29). Unmeasured factors could be correlated with both warfarin use and serious hypoglycemic events, leading to confounding. The findings may not generalize beyond the elderly Medicare population. WHAT THIS STUDY ADDS: A substantial positive association was seen between use of warfarin with glipizide/glimepiride and hospital admission/emergency department visits for hypoglycemia and related diagnoses, particularly in patients starting warfarin. The findings suggest the possibility of a significant drug interaction between these medications. FUNDING, COMPETING INTERESTS, DATA SHARING: JAR and DPG receive support from the National Institute on Aging, the Commonwealth Fund, and the Leonard D. Schaeffer Center for Health Policy and Economics at the University of Southern California. ABJ receives support from the NIH Office of the Director. No additional data are available.

Increase in overall mortality risk in patients with type 2 diabetes receiving glipizide, glyburide or glimepiride monotherapy versus metformin: a retrospective analysis.

AIMS: It remains uncertain if differences in mortality risk exist among the sulfonylureas, especially in patients with documented coronary artery disease (CAD). The purpose of this study was to assess the overall mortality risk of the individual sulfonylureas versus metformin in a large cohort of patients with type 2 diabetes. METHODS: A retrospective cohort study was conducted using an academic health centre enterprise-wide electronic health record (EHR) system to identify 23 915 patients with type 2 diabetes who initiated monotherapy with metformin (N = 12774), glipizide (N = 4325), glyburide (N = 4279) or glimepiride (N = 2537), ≥ 18 years of age, with and without a history of CAD, and not on insulin or a non-insulin injectable at baseline. The patients were followed for mortality by documentation in the EHR and Social Security Death Index. Multivariable Cox models with propensity analysis were used to compare cohorts. RESULTS: An increase in overall mortality risk was observed in the entire cohort with glipizide (HR 1.64; 95% CI 1.39-1.94), glyburide (HR 1.59; 95% CI 1.35-1.88), and glimepiride (HR 1.68; 95% CI 1.37-2.06) versus metformin; however, in those patients with documented CAD, a statistically significant increase in overall mortality risk was only found with glipizide (HR 1.41; 95% CI 1.07-1.87) and glyburide (HR 1.38; 95% CI 1.04-1.83) versus metformin. CONCLUSIONS: Glipizide, glyburide and glimepiride are associated with an increased risk of overall mortality versus metformin. Our results suggest that if a sulfonylurea is required to obtain glycaemic control, glimepiride may be the preferred sulfonylurea in those with underlying CAD.

The risk of overall mortality in patients with Type 2 diabetes receiving different combinations of sulfonylureas and metformin: a retrospective analysis.

AIMS: Sulfonylureas have been shown to increase mortality when used in combination with metformin. This may not be a class effect of sulfonylureas, but rather secondary to differences in properties inherent to the individual sulfonylureas (hypoglycaemic risk, sulfonylurea receptor selectivity and effects on myocardial ischemic preconditioning). The purpose of this study was to assess the risk of overall mortality in patients with Type 2 diabetes treated with different combinations of sulfonylureas and metformin. METHODS: A retrospective cohort study was conducted using an academic health center enterprise-wide electronic health record system to identify 7320 patients with Type 2 diabetes (3768 initiators of glyburide (glibenclamide) and metformin, 2277 initiators of glipizide and metformin and 1275 initiators of glimepiride and metformin), ≥ 18 years of age and not on insulin or a non-insulin injectable at baseline. The patients were followed for mortality by documentation in the electronic health record and Social Security Death Index. Multivariable Cox models with propensity analysis were used to compare cohorts. RESULTS: No statistically significant difference in overall mortality risk was observed among the different combinations of sulfonylureas and metformin: glimepiride and metformin vs. glipizide and metformin (HR 1.03; 95% CI 0.89-1.20), glimepiride and metformin vs. glyburide (glibenclamide) and metformin (HR 1.08; 95% CI 0.90-1.30), or with glipizide and metformin vs. glyburide (glibenclamide) and metformin (HR 1.05; 95% CI 0.95-1.15). CONCLUSIONS: Our results did not identify an increased mortality risk among the different combinations of sulfonylureas and metformin, suggesting that overall mortality is not substantially influenced by the choice of sulfonylurea.

Evaluation of in-stent restenosis in the APPROACH trial (Assessment on the Prevention of Progression by Rosiglitazone On Atherosclerosis in diabetes patients with Cardiovascular History).

To determine (1) the medium-term effect of rosiglitazone and glipizide on intra-stent neointima hyperplasia, (2) restenosis pattern as assessed by intra-vascular ultrasound (IVUS) and quantitative coronary angiography (QCA) in patients with T2DM and coronary artery disease. A total of 462 patients with T2DM were randomized to rosiglitazone or glipizide for up to 18 months in the APPROACH trial, and had evaluable baseline and follow-up IVUS examinations. There was no significant difference in the size of plaque behind stent between the rosiglitazone and glipizide groups at 18 months among those treated with a bare metal stent (-5.6 mm(3) vs. 1.9 mm(3); P = 0.61) or with a drug-eluting stent (12.1 mm(3) vs. 5.5 mm(3); P = 0.09). Similarly, there was no significant difference in percentage intimal hyperplasia volume between the rosiglitazone and glipizide groups at 18 months among those treated with a bare metal stent (24.1% vs. 19.8%; P = 0.38) or with a drug-eluting stent (9.8% vs. 8.3%; P = 0.57). QCA data (intra-stent late loss, intra-stent diameter stenosis or binary restenosis) were not different between the rosiglitazone and glipizide groups. This study suggests that both rosiglitazone and glipizide have a similar effect on neointimal growth at medium term follow-up, a finding that warrants investigation in dedicated randomized trials.

The risk of overall mortality in patients with type 2 diabetes receiving glipizide, glyburide, or glimepiride monotherapy: a retrospective analysis.

OBJECTIVE: Sulfonylureas have historically been analyzed as a medication class, which may be inappropriate given the differences in properties inherent to the individual sulfonylureas (hypoglycemic risk, sulfonylurea receptor selectivity, and effects on myocardial ischemic preconditioning). The purpose of this study was to assess the relationship of individual sulfonylureas and the risk of overall mortality in a large cohort of patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: A retrospective cohort study was conducted using an academic health center enterprise-wide electronic health record (EHR) system to identify 11,141 patients with type 2 diabetes (4,279 initiators of monotherapy with glyburide, 4,325 initiators of monotherapy with glipizide, and 2,537 initiators of monotherapy with glimepiride), >or=18 years of age with and without a history of coronary artery disease (CAD) and not on insulin or a noninsulin injectable at baseline. The patients were followed for mortality by documentation in the EHR and Social Security Death Index. Multivariable Cox models were used to compare cohorts. RESULTS: No statistically significant difference in the risk of overall mortality was observed among these agents in the entire cohort, but we did find evidence of a trend toward an increased overall mortality risk with glyburide versus glimepiride (hazard ratio 1.36 [95% CI 0.96-1.91]) and glipizide versus glimepiride (1.39 [0.99-1.96]) in those with documented CAD. CONCLUSIONS: Our results did not identify an increased mortality risk among the individual sulfonylureas but did suggest that glimepiride may be the preferred sulfonylurea in those with underlying CAD.

Assessment on the Prevention of Progression by Rosiglitazone on Atherosclerosis in diabetes patients with Cardiovascular History (APPROACH): study design and baseline characteristics.

BACKGROUND: Rosiglitazone, a thiazolidinedione, has effects on insulin sensitivity and cardiovascular risk factors that may favorably impact the progression of coronary atherosclerosis. METHODS: APPROACH is a double-blind randomized clinical trial comparing the effects of the insulin sensitizer rosiglitazone with the insulin secretagogue glipizide on the progression of coronary atherosclerosis. Patients with type 2 diabetes and coronary artery disease undergoing clinically indicated coronary angiography or percutaneous coronary intervention are randomized to receive rosiglitazone or glipizide for 18 months using a titration algorithm designed to provide comparable glycemic control between treatment groups. The primary end point is change in percent atheroma volume from baseline to study completion in a nonintervened coronary artery, as measured by intravascular ultrasound. Cardiovascular events are adjudicated by an end point committee. RESULTS: A total of 672 patients were randomized. The mean age was 61 years, hemoglobin A(1c) (HbA(1c)) 7.2%, body mass index 29.5 kg/m(2), and median duration of diabetes 4.8 years. At baseline, approximately half of the participants were receiving oral antidiabetic monotherapy (53.9%) with 27.5% receiving dual combination therapy and 17.9% treated with diet and exercise alone. Approximately two thirds of the participants (68%) had dyslipidemia, 79.9% hypertension, and 24% prior myocardial infarction. CONCLUSIONS: APPROACH has fully enrolled a high-risk patient population and will compare the glucose-independent effects of rosiglitazone and glipizide on the progression of coronary atherosclerosis, as well as provide additional data on the cardiovascular safety of rosiglitazone in patients with type 2 diabetes and coronary artery disease.

Economic model of first-line drug strategies to achieve recommended glycaemic control in newly diagnosed type 2 diabetes mellitus.

OBJECTIVE: To assess the short-term direct medical costs and effectiveness associated with achieving recommended glycaemic goals using commonly prescribed first-line oral antihyperglycaemic medications in type 2 diabetes mellitus. MATERIALS AND METHODS: A literature-based, decision-tree model was developed to project the number of patients achieving glycosylated haemoglobin values of <7% on oral therapies and the associated costs over a 3-year timeframe. For each first-line strategy, patients could progress to combination therapy using two or more agents prior to the introduction of insulin. The overall cost of treatment included costs (2001/2002 values; US dollars) of comprehensive medical care, laboratory tests, patient education, drug therapy, home glucose monitoring and adverse events. RESULTS: At 3 years, the overall cost of treatment for the various first-line strategies was 6,106 US dollars for glipizide gastrointestinal therapeutic system, 6,727 US dollars for metformin immediate release, 6,826 US dollars for metformin extended release, 7,141 US dollars for glibenclamide (glyburide)/metformin, 7,759 US dollars for rosiglitazone and 9,298 US dollars for repaglinide. Costs of comprehensive routine medical care ranged from approximately 1,538-2,128 US dollars in year 1 and from approximately 952-1,543 US dollars in subsequent years, for controlled and uncontrolled patients, respectively. Adverse events represented <1%, and drug therapies represented approximately 50%, of the overall cost, respectively. Substantial cost differences between the strategies were seen within the first year. Regardless of first-line therapy, patients progressed quickly to combination therapies, with effectiveness among the agents being similar. CONCLUSIONS: Short-term costs required to provide comprehensive diabetes care and achieve glycemic goals can be substantial. The model suggests a sulphonylurea strategy may provide similar effectiveness with cost savings over other agents and should be considered when selecting an initial drug therapy in newly diagnosed patients with type 2 diabetes mellitus.

Multicenter, randomized, double-masked, parallel-group assessment of simultaneous glipizide/metformin as second-line pharmacologic treatment for patients with type 2 diabetes mellitus that is inadequately controlled by a sulfonylurea.

BACKGROUND: Many patients with type 2 diabetes mellitus (DM) with inadequate long-term blood glucose control with sulfonylurea or metformin monotherapy require additional treatment. The synergistic effects of combining glipizide with metformin on glucose control may be realized by treating the primary effects of type 2 DM, impaired insulin secretion, and insulin resistance. OBJECTIVE: This study assessed therapy with glipizide/metformin combination tablets in patients with type 2 DM that is uncontrolled by at least half the maximum labeled daily dose of a sulfonylurea. METHODS: In this multicenter, double-masked, parallel-group, active-controlled study, patients were randomized to receive glipizide 30-mg, metformin 500-mg, or glipizide/metformin 5/500 mg tablets for 18 weeks (metformin and glipizide/metformin doses were titrated to achieve blood glucose control). Maximum total daily doses were glipizide 30 mg, metformin 2000 mg, and glipizide/ metformin 20/2000 mg. RESULTS: A total of 247 patients were included in the study. The mean (SD) age was 56.2 (10.1) years; 61.5% of patients were male; 70.0% were white, 15.8% were Hispanic/Latino, 13.0% were black, and 1.2% were Asian/Pacific Islanders. Patients were, on average, obese (mean [SD] body mass index, 31.3 [4.7] kg/m2), had moderate to severe hyperglycemia (mean [SD] glycated hemoglobin [HbA1c], 8.7% [1.1]), and had a mean (SD) DM duration of 6.5 (4.9) years. Glipizide/ metformin tablets controlled the HbA1c level more effectively than did either glipizide or metformin monotherapies (mean treatment differences, in favor of glipizide/ metformin, of -1.06% and -0.98%, respectively, P < 0.001). At study end, an HbA1c level < 7.0% was achieved in approximately 4-fold more patients who were treated with glipizide/metformin (36.3%) compared with glipizide (8.9%) or metformin (9.9%) monotherapies. Glipizide/metformin tablets also reduced the fasting plasma glucose (FPG) level and the 3-hour postprandial glucose area under the concentration-time curve more effectively than did either monotherapy, without increasing the fasting insulin level. The greater blood glucose control with glipizide/ metformin tablets was achieved at a mean daily dose of glipizide/metformin 17.5/1747 mg, compared with mean doses of glipizide 30.0 mg or metformin 1927 mg. Treatments were well tolerated, with a low incidence of symptoms of hypoglycemia evidenced by a fingerstick blood glucose measurement < or = 50 mg/dL in the combination group (12.6%); 1 patient discontinued the study treatment for this reason. No patient required medical assistance for hypoglycemia. CONCLUSIONS: Glipizide/metformin tablets were more effective than either glipizide or metformin monotherapy in controlling HbA1c and in reducing FPG compared with baseline in patients with blood glucose that was uncontrolled with previous sulfonylurea treatment. In addition, patients receiving glipizide/ metformin were more likely to achieve an HbA1c level < 7.0%. These results were consistent with the synergistic effects on insulin resistance and beta cell dysfunction. Glipizide/metformin was well tolerated, with a low incidence of hypoglycemia.

Comparison of serum fructosamine and blood glycosylated hemoglobin concentrations for assessment of glycemic control in cats with diabetes mellitus.

OBJECTIVE: To correlate serum fructosamine concentrations with established measures of glycemic control and to compare serum fructosamine and blood glycosylated hemoglobin (GHb) concentrations as a means for assessing glycemic control in diabetic cats. DESIGN: Longitudinal cohort study. ANIMALS: 26 healthy cats, 5 cats with stress-induced hyperglycemia, 15 untreated diabetic cats, and 36 treated diabetic cats. PROCEDURE: Control of glycemia was classified and monitored and serum fructosamine and blood GHb concentrations were measured for 12 poorly controlled diabetic cats before and after improving glycemic control, 8 well-controlled treated diabetic cats before and after glycemic control deteriorated, and 5 cats with diabetes mellitus before and after onset of stress-induced hyperglycemia. RESULTS: Mean serum fructosamine and blood GHb concentrations were significantly higher in untreated diabetic cats, compared with healthy cats, and in 24 poorly controlled diabetic cats, compared with 12 well-controlled diabetic cats. Mean serum fructosamine and blood GHb concentrations decreased significantly in 12 poorly controlled diabetic cats after improving glycemic control and increased significantly in 8 well-controlled diabetic cats after glycemic control deteriorated. A significant stress-induced increase in mean blood glucose concentration was evident 12 hours after insulin administration, but not in 5 docile diabetic cats that became fractious. CLINICAL IMPLICATIONS: Serum fructosamine and blood GHb concentrations are clinically useful tools for monitoring control of glycemia in cats with diabetes mellitus.

Health economic benefits and quality of life during improved glycemic control in patients with type 2 diabetes mellitus: a randomized, controlled, double-blind trial.

CONTEXT: Although the long-term health benefits of good glycemic control in patients with diabetes are well documented, shorter-term quality of life (QOL) and economic savings generally have been reported to be minimal or absent. OBJECTIVE: To examine short-term outcomes of glycemic control in type 2 diabetes mellitus (DM). DESIGN: Double-blind, randomized, placebo-controlled, parallel trial. SETTING: Sixty-two sites in the United States. PARTICIPANTS: A total of 569 male and female volunteers with type 2 DM. INTERVENTION: After a 3-week, single-blind placebo-washout period, participants were randomized to diet and titration with either 5 to 20 mg of glipizide gastrointestinal therapeutic system (GITS) (n = 377) or placebo (n = 192) for 12 weeks. MAIN OUTCOME MEASURES: Change from baseline in glucose and hemoglobin A1c (HbA1c) levels and symptom distress, QOL, and health economic indicators by questionnaires and diaries. RESULTS: After 12 weeks, mean (+/-SE) HbA1c and fasting blood glucose levels decreased with active therapy (glipizide GITS) vs placebo (7.5% 0.1% vs 9.3%+/-0.1% and 7.0+/-0.1 mmol/L [126+/-2 mg/dL] vs 9.3+/-0.2 mmol/L [168+/-4 mg/ dL], respectively; P<.001). Quality-of-life treatment differences (SD units) for symptom distress (+0.59; P<.001), general perceived health (+0.36; P= .004), cognitive functioning (+0.34; P=.005), and the overall visual analog scale (VAS) (+0.24; P=.04) were significantly more favorable for active therapy. Subscales of acuity (+0.38; P=.002), VAS emotional health (+0.35; P=.003), general health (+0.27; P=.01), sleep (+0.26; P=.04), depression (+0.25; P=.05), disorientation and detachment (+0.23; P= .05), and vitality (+0.22; P=.04) were most affected. Favorable health economic outcomes for glipizide GITS included higher retained employment (97% vs 85%; P<.001), greater productive capacity (99% vs 87%; P<.001), less absenteeism (losses = $24 vs $115 per worker per month; P<.001), fewer bed-days (losses = $1539 vs $1843 per 1000 person-days; P=.05), and fewer restricted-activity days (losses = $2660 vs $4275 per 1000 person-days; P=.01). CONCLUSIONS: Improved glycemic control of type 2 DM is associated with substantial short-term symptomatic, QOL, and health economic benefits.

Glycosylated hemoglobin concentration for assessment of glycemic control in diabetic cats.

Blood glycosylated hemoglobin (GHb) concentration was quantified in 84 healthy cats, 9 cats with stress-induced hyperglycemia, 37 cats with newly diagnosed diabetes mellitus, and 122 diabetic cats treated with insulin or glipizide. Diabetic control was classified as good or poor in insulin-treated or glipizide-treated cats based on review of history, physical examination findings, changes in body weight, and measurement of blood glucose concentrations. Blood GHb concentration was determined using an affinity chromatography assay. Mean blood GHb concentration was similar for healthy normoglycemic cats and cats with transient, stress-induced hyperglycemia, but was significantly (P < .001) higher in untreated diabetic cats when compared with healthy normoglycemic cats. Mean blood GHb concentration was significantly (P < .001) higher in 84 cats with poorly controlled diabetes mellitus when compared with 38 cats in which the disease was well controlled. Mean blood GHb concentration decreased significantly (P < .01) in 6 cats with untreated diabetes mellitus after insulin and dietary treatment. A similar significant (P < .01) decrease in mean blood GHb concentration occurred in 7 cats with poorly controlled diabetes mellitus after diabetic control was improved by an increase in insulin dosage from 1.1 +/- 0.9 to 1.4 +/- 0.6 U/kg/ 24 h and by feeding a diet containing increased fiber content and in 6 cats with transient diabetes mellitus 8.2 +/- 0.6 weeks after discontinuing insulin treatment. There was a significant (P < .01) stress-induced increase in mean fasting blood glucose concentration and mean blood glucose concentration for 12 hours after administration of insulin or glipizide but no change in mean blood GHb concentration in 5 docile diabetic cats 12.2 +/- 0.4 weeks after the cats became fractious as a result of frequent hospitalizations and blood samplings. Results of this study suggest that evaluation of blood GHb concentration may be a clinically useful tool for monitoring glycemic control of diabetes in cats.

Cost-effectiveness analyses of the conversion of patients with non-insulin-dependent diabetes mellitus from glipizide to glyburide and of the accompanying pharmacy follow-up clinic.

At the Department of Veteran's Affairs Outpatient Clinic in Columbus, Ohio, patients with non-insulin-dependent diabetes mellitus who were receiving glipizide therapy were converted to glyburide therapy over a 6-month period starting in mid-1993. A pharmacy follow-up clinic was instituted to help patients with problems associated with the transition. The conversion was intended to reduce costs by converting from a more expensive to a less expensive drug (in terms of acquisition cost) within the same therapeutic class. An initial analysis of the conversion indicated a savings of $65,000.00 to the Department of Veterans' Affairs (VA) based on the drug acquisition cost differential alone. The purpose of our study was to retrospectively evaluate the cost-effectiveness of the conversion and pharmacy follow-up clinic from the perspective of the VA pharmacy department. Relevant costs and effectiveness (percentage of patients who achieved good glycemic control) were examined for three groups: group I--patients who were treated with glipizide, group II--patients who were treated with glipizide; group II--patients who were switched from glipizide to glyburide, accompanied by a pharmacy follow-up clinic; and group III--patients who were switched from glipizide to glyburide, with no follow-up clinic. Overall, group II had the lowest costs, and group II had to be the most effective. Cost-II effectiveness analysis indicated that, in general, the conversion from glipizide to glyburide was cost-effective. Incremental analysis performed for the follow-up group over the no follow-up group showed that for every 1% of patients who achieved good glycemic control, the VA would spend $1.01 more for the follow-up groups. This was considered to be cost-effective for the VA.

Formulary conversion from glipizide to glyburide: a cost-minimization analysis.

Economic pressure prompted us to search for and implement cost-saving strategies at Bronx Municipal Hospital. This paper describes a cost-minimization analysis of the impact of formulary substitution of glyburide for glipizide on glycemic control, safety, and costs. In 76 patients with computerized prescription records, switching from a mean daily glipizide dose of 19 mg to a mean daily glyburide dose of 10.2 mg did not affect glycemic control. A subset of 33 elderly patients experienced only three drug-related adverse events during the 2-year observation period. The conversion program yielded a 51% reduction in overall expenditures for oral hypoglycemic agents between 1991 and 1993. These findings indicate that our conversion program was successful, which has led to its becoming a model for other New York City municipal outpatient pharmacies.

Conversion from glipizide to glyburide: long-term follow-up of a cost-impact survey focusing on the elderly.

The appropriate use of second-generation oral hypoglycemic agents is limited by the lack of definitive guidelines for their use in elderly diabetic patients and controversy over relative dosing equivalence. We previously conducted a survey to determine the feasibility and cost of converting diabetic patients from glipizide to glyburide. This new survey provides an extended, 24-month follow-up in 210 patients and focuses on findings in elderly patients. The mean final daily dose of glyburide (11.6 mg) was lower than the preconversion dose of glipizide (18.7 mg) (P < or = 0.0001). One hundred forty-one (67%) patients successfully continued glyburide for 24 months, including 103 (73%) patients who were 65 years of age or older. There was no apparent correlation between age and final dose of glyburide, ability to continue glyburide, or risk of stopping glyburide. The conversion program reduced the mean daily dose after switching from glipizide to glyburide, which was preserved throughout the observation period. The program also conferred a 49% savings in the projected 2-year expenditures for second-generation oral hypoglycemic agents.

Evaluation of glipizide and glyburide in a health maintenance organization.

OBJECTIVE: To determine if there was a difference in the long-term glycemic control, average daily dose, and cost of therapy in patients with noninsulin-dependent diabetes mellitus (NIDDM) treated with glyburide and glipizide in a health maintenance organization (HMO). DESIGN: Retrospective evaluation of medical and pharmacy records. SETTING: Multispecialty group practice HMO. PATIENTS: 140 NIDDM patients being treated with either glyburide (n = 70) or glipizide (n = 70) were randomly selected from the populations of patients receiving either drug using computerized pharmacy records. MAIN OUTCOME MEASURE: Mean daily doses and blood glucose measurements (fasting blood glucose, random blood glucose, hemoglobin A1C) were stratified in 3-month periods from the time the drug therapy was started or the patient first presented to the clinic for a total of 18 months. Long-term glycemic control was defined as fasting blood glucose less than 8.33 mmol/L (150 mg/dL). RESULTS: The groups were comparable with regard to age (53.4 y glyburide, 56.7 y glipizide), gender (43 M:27 F glyburide, 47 M:23 F glipizide), race (38 W/16 B/16 H glyburide, 45 W/16 B/9 H glipizide), concurrent medical conditions, adverse effects, and compliance. Long-term glycemic control was similar in both groups. Although the number of subjects who were controlled (by definition) tended to be greater in the glyburide group, no clinical or statistical difference was found. There was no statistical difference in mean daily dose between the ethnic groups, but the small numbers preclude further analysis. The glipizide group had a larger percentage increase in dose within the first year than did the glyburide group; however, the percentage increase from the 3-month dose was similar after 18 months (22.7 percent glyburide, 27.5 percent glipizide.) Average daily cost of therapy, based on mean daily dose, was slightly lower for glyburide-treated patients. CONCLUSIONS: If glycemic control is similar with glyburide and glipizide, as seen in this study, economic considerations regarding choice of therapy and formulary inclusion may be appropriate.

Glyburide and glipizide, second-generation oral sulfonylurea hypoglycemic agents.

The chemistry, pharmacology, pharmacokinetics, clinical efficacy, adverse effects, and dosage of glyburide and glipizide, two second-generation oral sulfonylurea hypoglycemic agents, are reviewed. Glyburide and glipizide are well absorbed after oral administration. The absorption of glipizide is delayed by food; in contrast, glyburide absorption does not seem to be affected by administration with meals. Both drugs are extensively metabolized by the liver. A two-compartment open model adequately describes the pharmacokinetics of these drugs. The apparent elimination half-life of glyburide in oral dosage forms available in the United States ranges from 7 to 10 hours. Glipizide has a terminal elimination half-life of 2-7 hours. The effects of renal and hepatic disease on the pharmacokinetics of glyburide and glipizide have not been well studied. Based on controlled, comparative studies in patients with new-onset, diet-failed, Type II diabetes, glyburide appears to be at least as effective as chlorpropamide and tolazamide in controlling blood glucose. Glipizide has shown efficacy comparable to or greater than that of chlorpropamide and tolbutamide. Glyburide and glipizide appear to be comparable in terms of their ability to control fasting blood glucose in Type II diabetics. The recommended initial dosage of glyburide in newly diagnosed Type II diabetics is 2.5-5 mg once daily. For glipizide, the initial dosage should be 5 mg once daily. Elderly or debilitated patients and those with renal or hepatic impairment should be started on lower dosages initially. Glyburide and glipizide have adverse effects that are similar to those observed with the first-generation oral hypoglycemic agents. Glyburide and glipizide do not appear to offer major therapeutic advantages over first-generation oral sulfonylurea hypoglycemic agents. However, they may represent therapeutic alternatives for some patients who do not respond satisfactorily to other sulfonylureas.