Krystal L Edwards

Texas Tech University Health Sciences Center, Lubbock, TX, United States

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Publications (15)20.72 Total impact

  • Derrica Y Walker, Krystal L Edwards
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    ABSTRACT: Current evidence on statin agents as potential alternatives or adjuncts to corticosteroid therapy for asthma is reviewed. Research showing antiinflammatory and antioxidant effects of statins in animal models suggested that the cholesterol-lowering drugs might be useful in mitigating the adverse effects of long-term corticosteroid therapy in patients with asthma, but studies in humans have yielded mixed results. Two small placebo-controlled clinical trials indicated that statins were not effective in combating asthmatic inflammatory processes, and trials of statins as adjunctive therapy have indicated minimal steroid-sparing benefits. In two studies involving a total of more than 1000 current and former smokers with asthma, statin use correlated with reduced acute asthma exacerbations and a slower decline of lung function in some patients. A large population-based study (n = 3965) found that statin therapy was associated with a significantly reduced risk of hospitalization for asthma after an average follow-up period of about 4.5 years; a smaller U.S. retrospective cohort study indicated a significantly lower 1-year rate of asthma-related emergency room visits among patients receiving statins relative to those not using statins (9.08% versus 4.18%). Much of the research on statins and asthma has not controlled for confounding influences such as patient comorbidities and concomitant medication use. Clinical trials have shown that statin therapy is not superior to and does not enhance the beneficial effects of inhaled corticosteroids for the treatment of asthma. Some evidence suggests that statins may help preserve lung function in cigarette smokers with obstructive pulmonary disease and reduce hospitalizations in asthmatic smokers and nonsmokers.
    American journal of health-system pharmacy: AJHP: official journal of the American Society of Health-System Pharmacists 10/2013; 70(19):1661-9. · 2.10 Impact Factor
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    ABSTRACT: Abstract The glucagon-like peptide-1 receptor agonists, exenatide and liraglutide, offer a unique mechanism in the treatment of type 2 diabetes mellitus (T2DM) as part of the incretin system. Their mechanism of action is to increase insulin secretion, decrease glucagon release, reduce food intake, and slow gastric emptying. They target postprandial blood glucose values and have some effect on fasting levels as well. In addition, they promote weight loss and may help to preserve β-cell function, both major problems in T2DM patients. Changes in hemoglobin A1c are similar to those produced by other T2DM agents, including thiazolidinediones, low-dose metformin, and sulfonylureas, and better than those caused by α-reductase inhibitors and dipeptidyl peptidase-4 inhibitors. These agents have been safely studied in combination with metformin, sulfonylureas, meglitinides, thiazolidinediones, and insulin therapy. Overall, data are limited for head-to-head comparisons, but it appears that liraglutide may have better efficacy and tolerability compared with exenatide; however, more studies are needed. They are overall well tolerated, with the main adverse events being similar to those with metformin (gastrointestinal intolerances that are transient and dose dependent). However, patients must be monitored for pancreatitis as a rare but possible side effect. For T2DM patients willing to use an injectable agent, exenatide and liraglutide offer another therapeutic option to control hyperglycemia with the potential for weight loss and may be combined with other agents safely.
    Diabetes Technology &amp Therapeutics 07/2012; 14(10):951-67. · 2.21 Impact Factor
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    ABSTRACT: Dipeptidyl peptidase -4 inhibitors represent a novel way to augment the incretin system and one of the newest class of medications in the treatment of type 2 diabetes mellitus. Their mechanism of action is to decrease the inactivation of glucagon-like peptide 1 and glucose-dependent insulinotropic polypeptide, both of which are involved in maintaining euglycemia subsequent to carbohydrate intake. Currently investigated agents include sitagliptin, vildagliptin, saxagliptin, linagliptin, and alogliptin. Each agent has been shown to provide significant improvements in glycemic control compared to placebo. They are effective when added to other oral diabetes agents and in the cases of sitagliptin, vildagliptin, and alogliptin in addition to insulin. These agents may not provide as significant improvement in glucose concentrations as some other medications including metformin, thiazolidinediones, or glucagon-like peptide 1 agonists. The lack of head to head clinical data comparing the various dipeptidyl peptidase 4 inhibitors does not allow for specific recommendations if one agent is more effective or safer than another within the class. Their side effect profile suggests they are very well tolerated and have few drug interactions. For patients with mildly elevated glucose concentrations, they are therapeutic options in both drug-naive patients as well as those not optimally controlled on other diabetes medications.
    Current diabetes reviews 03/2012; 8(3):169-82.
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    ABSTRACT: Pivotal ranolazine trials did not require optimization of conventional medical therapy including coronary revascularization and antianginal drug therapy prior to ranolazine use. This case series describes the use of ranolazine for the treatment of chronic stable angina refractory to maximal medical treatment in a veterans population. A total of 18 patients with a median age of 66 years were identified. All patients had prior percutaneous coronary intervention and/or coronary artery bypass graft surgery; 83% had three-vessel coronary artery disease, with left main disease present in 39% of patients. Prior to initiating ranolazine, antianginal use consisted of beta blockers (94%), long-acting nitrates (83%) and calcium channel blockers (61%). Median blood pressure (116.2/61.8 mmHg) and pulse (65 beats per min) were controlled. Median preranolazine angina episodes and sublingual nitroglycerin (SLNTG) doses per week were 14 and 10, respectively, with a Canadian Cardiovascular Society (CCS) angina grade of III-IV in 67% of patients. After initiation of ranolazine, median angina episodes per week and SLNTG doses used per week decreased to 0.7 and 0, respectively, with CCS grade of III-IV declining to 17%. Of the 18 subjects enrolled, 44% had complete resolution of angina episodes. The addition of ranolazine to maximally tolerated conventional antianginal drug therapy post coronary revascularization was associated with decreases in angina episodes and SLNTG utilization and improvement in CCS angina grades. Ranolazine may provide an effective treatment option for revascularized patients with refractory angina.
    Cardiovascular revascularization medicine: including molecular interventions 08/2011; 13(2):141.e1-5.
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    ABSTRACT: Diabetes mellitus has reached epidemic proportions worldwide, eliciting extensive research on both the disease process and its treatment. Regardless of diabetes type, the progressive nature of the disease makes insulin the long-term mainstay of diabetes management. Recently, the insulin analog glargine was reported in several epidemiologic studies to be associated with an increased risk of cancer. Inconsistent study results and media attention have caused much angst and concern to health care professionals and the general population. A clear understanding of the current evidence is needed to adequately develop a patient-oriented risk:benefit assessment. Members of the Endocrine and Metabolism Practice and Research Network of the American College of Clinical Pharmacy evaluated available evidence to provide guidance and discussion on the risk of cancer with insulin glargine use. We believe the current link between insulin glargine and cancer is tenuous but merits further evaluation. An independent analysis of all available glargine clinical trial data should be performed, and a vigorous postmarketing safety study of glargine should be conducted. Until more substantial data are available, however, neither the choice of initial insulin therapy nor insulin maintenance regimens should be influenced by the current information linking insulin glargine to cancer.
    Pharmacotherapy 09/2010; 30(9):955-65. · 2.31 Impact Factor
  • Journal of Antivirals and Antiretrovirals 01/2009; 3(3):212-212.
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    ABSTRACT: Type 2 diabetes mellitus (T2DM) is a coronary heart disease (CHD) risk equivalent warranting aggressive management of dyslipidemia and tight glycemic control. Recent reports demonstrate a paradoxic decrease in high-density lipoprotein cholesterol (HDL-C) with thiazolidinedione (TZD) and fibrate combination therapy. Evaluate change in HDL-C from start of combination therapy to 1 year and assess the proportion, characteristics, and regimens of patients who developed a ≥20% decrease in HDL-C from baseline. Patients with T2DM treated concurrently with a combination of TZD and fibrate were identified through retrospective query from a Veterans Affairs medical center database. HDL-C was recorded for 1 year after patients started combination therapy. Logistic regression analysis was performed to determine any predictors of HDL-C change. A total of 322 patients were included in the analysis. There was no significant differences in mean ± standard deviation HDL-C from baseline to end point (36.8 ± 8.5 to 40.3 ± 11.8 mg/dL; P = 0.097). There was a subset of patients identified (13%; n = 43) on combination therapy who experienced a ≥20% reduction in HDL-C. Of these patients, a decrease in HDL-C was more likely to occur with fenofibrate-based regimens (odds ratio 3.08, 95% confidence interval 1.22 to 7.75; P = 0.018). There was a trend toward more of these patients in this subset to have the combination of rosiglitazone and fenofibrate in their profiles (odds ratio 2.82, 95% confidence interval 0.98 to 8.0; P = 0.064). Our study demonstrated that a subset of patients with T2DM experienced a paradoxic decrease in HDL-C when taking a fibrate and TZD combination.
    Journal of Clinical Lipidology 12/2008; 2(6):447-52. · 3.59 Impact Factor
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    ABSTRACT: Patients with type 2 diabetes mellitus often begin treatment by taking oral agents, usually metformin or a sulfonylurea, and then progress to the combination of these two agents. Most patients often require three or more agents or a change to an insulin regimen. However, no guidelines are available to aid the clinician in the decision-making process for selecting the third agent. Many options are available for additional therapy, including thiazolidinediones, intermediate- and long-acting insulins, exenatide, and dipeptidyl peptidase-4 inhibitors. Although the American Diabetes Association recommends metformin as first-line therapy, it does not give exact specifications for second- and third-line agents but only summarizes clinical data and options about each therapeutic drug class. Guidelines from the American College of Endocrinology and American Association of Clinical Endocrinologists recommend several options depending on the patient's hemoglobin A(1c) level. Therefore, a standard of care cannot be provided; rather, clinicians must evaluate each patient to ascertain that patient's optimum therapy. In doing so, clinicians need to be familiar with the efficacy, safety, and cost of each agent.
    Pharmacotherapy 05/2008; 28(4):506-21. · 2.31 Impact Factor
  • Journal of Clinical Lipidology - J CLIN LIPIDOL. 01/2008; 2(3):205-205.
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    ABSTRACT: Abnormalities in lipid metabolism are a well-described consequence of human immunodeficiency virus (HIV) infection being treated with highly active antiretroviral therapies (HAART). The purpose of this study is to evaluate the lipid-lowering efficacy and safety of ezetimibe added to existing hydroxy methylglutaryl coenzyme A reductase (statin) therapy in HIV-infected patients with hyperlipidemia. This is a retrospective study utilizing a comprehensive electronic patient registry to identify all adult HIV-infected patients seen at the Dallas Veterans Affairs (VA) Medical Center during a 4-year period from October 1, 2002 through October 1, 2006. A total of 26 HIV-infected patients initiated on ezetimibe 10 mg were identified, with 14 adult males meeting strict criteria for inclusion. Median age was 54 years (interquartile range [IQR], 45-59) with a median duration of HIV of 13 years, CD4 count of 513 cells/mm(3) (IQR, 289-736), and 9 of 14 patients had undetectable viral loads at baseline. Initiation of ezetimibe 10 mg resulted in a significant decrease in total cholesterol (TC) from baseline (-12.9%, P = 0.001); low-density lipoprotein cholesterol (LDL-C; -25.7%, P = 0.001); and non-high-density lipoprotein cholesterol (non-HDL-C; -23.9%, P = 0.001). There was also a nonsignificant decrease in triglycerides (15.8%, P = 0.43), and an increase in number of patients achieving National Cholesterol Education Program/Adult Treatment Panel III goal for LDL-C after initiation of ezetimibe (+20.9%, P = 0.125). These improvements occurred without adverse effects or changes in virologic and immunologic control. Addition of ezetimibe to existing statin therapy in HIV-infected VA patients treated with HAART significantly reduces TC, LDL-C, and non-HDL-C concentrations without apparent side effects or compromising of virologic control.
    Journal of Clinical Lipidology 12/2007; 1(6):634-9. · 3.59 Impact Factor
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    ABSTRACT: The rising prevalence and health burden of diabetes mellitus require that new approaches for prevention among high-risk populations be evaluated. Emerging evidence from the prospective evaluations of secondary and tertiary outcomes and from retrospective evaluations in randomized controlled trials suggests that angiotensin-converting enzyme (ACE) inhibitors and angiotensin II type 1 receptor blockers (ARBs) may reduce the occurrence of new-onset diabetes. Therefore, we each independently searched MEDLINE for randomized controlled trials from January 1966-October 2005 that used an ACE inhibitor or ARB as a primary intervention versus a control group not receiving an ACE inhibitor or ARB and that reported the occurrence of diabetes. Thirteen trials were identified. In each of the 13 studies, the frequency of diabetes in the ACE inhibitor or ARB groups was lower than that in the control groups. In addition, it was consistent in that no study significantly excluded any benefit from ACE inhibitors or ARBs on the rate of new-onset diabetes. The combined occurrence of new-onset diabetes in all 13 studies was 2249 cases among 31,283 patients (7.2%) in the ACE inhibitor or ARB group versus 3230 cases among 35,988 patients (9.0%) in the control group. The combined relative risk of diabetes was 0.80, with a 95% confidence interval of 0.76-0.84, based on a two-sided alpha of 0.05, in favor of ACE inhibitors and ARBs. This observation needs to be confirmed by randomized controlled trials with the frequency of diabetes as the primary prospective end point.
    Pharmacotherapy 10/2006; 26(9):1297-306. · 2.31 Impact Factor
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    ABSTRACT: Clinical data suggest that thiazolidinediones--specifically, rosiglitazone and pioglitazone--may improve cardiovascular risk factors through multiple mechanisms. Low insulin sensitivity has been described as an independent risk factor for coronary artery disease and cerebrovascular disease. Patients with insulin resistance often have several known risk factors, such as obesity, dyslipidemia, and hypertension. Other emerging risk factors may be prevalent in patients with insulin resistance, such as hyperinsulinemia, elevated C-reactive protein, elevated plasminogen activator inhibitor levels, and small, dense, low-density lipoproteins. The only available drug class that primarily targets insulin resistance is the thiazolidinediones. These drugs have shown efficacy in affecting surrogate markers of cardiovascular risk in patients with diabetes mellitus. Alterations in these risk factors are likely due to their effects on improving insulin sensitivity and/or glycemic control. Trials to assess whether thiazolidinediones actually reduce cardiovascular outcomes are continuing.
    Pharmacotherapy 03/2006; 26(2):168-81. · 2.31 Impact Factor
  • Krystal L. Edwards, Brian K. Irons, Tom Xu
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    ABSTRACT: Objective: To better understand exenatide’s role in the treatment of type 2 diabetes, this analysis assessed its cost-effectiveness in comparison to an intermediate (NPH) and long-acting insulin (glargine). Exenatide is a recently approved medication for the treatment of type 2 diabetes for use in addition to frequently used oral diabetes medications. Methods: Two studies were identified by a Medline search (1996-Oct 2005) that were similar in study duration, baseline glycemic control, population size, and primary outcomes to appropriately assess the cost-effectiveness of either insulin in comparison to exenatide on both glycemic and weight control. Results: Both NPH and glargine appear to be more cost effective than exenatide with respect to glycemic control (incremental CE ratios -1,968 and -65,520 respectively). Exenatide appears to be more cost effective for reductions in body weight than either NPH (CE ratio 235) or glargine (CE ratio 128). Conclusions Compared to intermediate and long-acting insulin therapies, exenatide does not appear to be as cost effective for the treatment of type 2 diabetes.
    Pharmacy Practice (granada). 01/2006; 4(3).
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    Krystal L Edwards, Brian K Irons, Tom Xu
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    ABSTRACT: Objective: To better understand exenatide¿s role in the treatment of type 2 diabetes, this analysis assessed its cost-effectiveness in comparison to an intermediate (NPH) and long-acting insulin (glargine). Exenatide is a recently approved medication for the treatment of type 2 diabetes for use in addition to frequently used oral diabetes medications. Methods: Two studies were identified by a Medline search (1996-Oct 2005) that were similar in study duration, baseline glycemic control, population size, and primary outcomes to appropriately assess the cost-effectiveness of either insulin in comparison to exenatide on both glycemic and weight control. Results: Both NPH and glargine appear to be more cost effective than exenatide with respect to glycemic control (incremental CE ratios -1,968 and -65,520 respectively). Exenatide appears to be more cost effective for reductions in body weight than either NPH (CE ratio 235) or glargine (CE ratio 128). Conclusions Compared to intermediate and long-acting insulin therapies, exenatide does not appear to be as cost effective for the treatment of type 2 diabetes.
    Pharmacy Practice, ISSN 1886-3655, Vol. 4, Nº. 3, 2006, pags. 129-133. 01/2006;
  • Krystal L. EDWARDS, Brian K. IRONS, Tom XU
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    ABSTRACT: Objective: To better understand exenatide's role in the treatment of type 2 diabetes, this analysis assessed its cost-effectiveness in comparison to an intermediate (NPH) and long-acting insulin (glargine). Exenatide is a recently approved medication for the treatment of type 2 diabetes for use in addition to frequently used oral diabetes medications. Methods: Two studies were identified by a Medline search (1996-Oct 2005) that were similar in study duration, baseline glycemic control, population size, and primary outcomes to appropriately assess the cost-effectiveness of either insulin in comparison to exenatide on both glycemic and weight control. Results: Both NPH and glargine appear to be more cost effective than exenatide with respect to glycemic control (incremental CE ratios -1,968 and -65,520 respectively). Exenatide appears to be more cost effective for reductions in body weight than either NPH (CE ratio 235) or glargine (CE ratio 128).