A retrospective, comparative evaluation of dysglycemias in hospitalized patients receiving gatifloxacin, levofloxacin, ciprofloxacin, or ceftriaxone

Drug Utilization Evaluation Study of Ciprofloxacin Use and Adverse Events Occurrence: Role of Community Pharmacists

Background: Antimicrobial resistance is a global health crisis threatening optimal management of infectious diseases. Ciprofloxacin is a widely used fluoroquinolone in various disease conditions. Resistance against ciprofloxacin is increasing, leading to nonoptimal management of patients. Thus, the aim of this study was to assess ciprofloxacin use in the community setting in terms of appropriate prescribing, dosing, frequency, and duration of use. Methods: A cross-sectional, retrospective study was conducted by community pharmacists in 5 community pharmacies in Egypt from September 2021 to February 2022. Patients prescribed oral ciprofloxacin during the period of the study were included. Data on demographics, indications for ciprofloxacin, dosing regimen, adverse events, and drug interactions were collected. Results: A total of 151 patients' record indicated for ciprofloxacin were included in the study, of whom 44.4% were men and 55.6% were women who were neither pregnant nor lactating. Based on international guidelines, 96.69% ciprofloxacin prescriptions were appropriate; 96.03% contained correct ciprofloxacin dosing whereas 3.97% were overdose. A total of 90. 73% had correct frequency of administration and 96.03% records had correct durations. Only 1.99% of patients were ≤18 years of age, which is an absolute contraindication. Interacting drugs with ciprofloxacin were 28.5% with acetaminophen, 31.1% with ibuprofen, 16.6% with antacids, 21.2% with chlorpheniramine, and 7.9% with prednisolone. Adverse events included 1.32% hypoglycemia, 0.66% hyperglycemia, 3.97% tendinitis, and 2.65% QTc (heart rate-corrected QT interval) prolongation. Conclusion and relevance: Ciprofloxacin use in community pharmacies is appropriate according to international guidelines. Ongoing drug utilization evaluation is necessary to ensure rational drug use, which in turn can decrease resistance rates.

Fluoroquinolone-induced Glycaemic Aberrations: Could Quinolones be Repurposed to Serve as New Antidiabetic Agents?

Nalidixic acid is a synthetic antibiotic discovered in the 1960s during the synthesis of chloroquine, an effective drug for treating malaria. Nalidixic acid became the backbone for developing quinolones that are now widely used clinically for the treatment of various bacterial infections. The mechanism of action of quinolone involves the inhibition of topoisomerase II and topoisomerase IV. In attempts to improve the potency of fluoroquinolones, modifications were made; these modifications resulted in the emergence of newer generations of fluoroquinolones. Also, due to these modifications, several side effects were noted, including blood glucose control aberrations. Among fluoroquinolones that disrupt glucose homeostasis is gatifloxacin, which is in the third-generation category. Fluoroquinolones have been demonstrated to induce glycaemic aberrations by enhancing pancreatic cells' insulin secretion and interaction with antidiabetic agents via inhibition of cytochrome P450 enzymes. Considering their ability to induce hypoglycaemia, few studies have reported repurposing of quinolones as antidiabetic agents. Hyperglycaemia has also been reported to often precede hypoglycaemia. Due to the ability to decrease blood glucose, it is not surprising that some authors have reported novel quinolone derivates with antidiabetic properties in experimental studies. However, there is still a paucity of data regarding the effect of quinolones derivatives on glycaemic control. Understanding how fluoroquinolones lower blood glucose concentration could serve as the basis for developing novel quinolone derivatives with the sole purpose of lowering blood glucose concentrations. Although there are various conventional anti-hyperglycaemic agents, due to their associated shortfalls as well as an increase in the prevalence of diabetes, the discovery and development of new antidiabetics are warranted.

Risk for hypoglycemic emergency with levofloxacin use, a population-based propensity score matched nested case-control study

Potential association between oral levofloxacin use and hypoglycemic emergency (HE) have been established. However, a large epidemiological study is required to verify this observation. This study aimed to determine if use of oral levofloxacin increased the risk of HE. The nationwide database between 1999 and 2013, including 1.6 million patients with type 2 diabetes (T2D), was used to conduct a nested case-control study. Cases and controls comprised of patients with and without HE, respectively. To avoid indication bias the control subjects were chosen through propensity score matching with cases in a 10-fold ratio. T2D severity was classified based on the adjusted diabetic complication severity index score. 26,695 and 266,950 matched patients with T2D, were finally used as cases and controls, respectively, for the analysis. Multivariate logistic regression analysis showed that antibiotic use was associated with an increased risk for HE (adjusted odds ratio (aOR) = 6.08, 95% confidence interval (95% CI): 5.79–6.38). When compared with antibiotic non-users, those who used fluoroquinolones and sulfonamides displayed the highest (aOR = 12.05, 95% CI: 10.66–13.61) and second highest (aOR = 7.20, 95% CI: 6.29–8.24) risks of HE, respectively. The associated risk for HE was significantly higher with levofloxacin than that with cephalosporins (aOR = 5.13, 95% CI: 2.28–11.52) and penicillin (aOR = 9.40, 95% CI: 2.25–39.24). In the joint effect analyses, the risk for HE increased with the combination of levofloxacin with insulin (aOR = 8.42, 95% CI: 1.91–37.00) or sulfonylurea (aOR = 3.56, 95% CI: 1.12–11.33). Use of oral levofloxacin, compared to that of other antibiotics, was found to be significantly associated with HE in T2D patients. Clinicians should exercise caution while prescribing levofloxacin, especially when combined with insulin or sulfonylurea.

How Safe are Fluoroquinolones for Diabetic Patients? A Systematic Review of Dysglycemic and Neuropathic Effects of Fluoroquinolones

Introduction

The US Food and Drug Administration issued safety warnings about neuropathy in 2013 and dysglycemia in 2018 caused by fluoroquinolone use, mainly based on case reports and case series. We conducted this systematic review to evaluate the safety of fluoroquinolones in diabetic patients by investigating their dysglycemic and neuropathic effects.

Methods

PubMed, Scopus, and Google Scholar were searched for randomized controlled trials and observational studies published from inception till September 2019 evaluating the safety of fluoroquinolones. Efficacy studies of fluoroquinolones reporting these adverse effects were also included. Primary outcomes were hypoglycemia, hyperglycemia, and neuropathy among patients with or without diabetes and treated with fluoroquinolones compared with placebo or other antibiotics. The Cochrane Collaboration tool for randomized controlled trials and modified Newcastle-Ottawa quality-assessment scale were used for assessment of the included studies.

Results and Discussion

A total of 725 studies were identified in the initial search. After screening of titles and abstracts and full-text review, 16 articles fulfilled the inclusion criteria. The sampled patients were aged 30-78 years. Hyperglycemia was reported in 1,588 patients that received fluoroquinolone among eight studies with 4,663 patients, and hypoglycemia was reported in 2,179 patients that received fluoroquinolones among eleven studies with 6,208 patients. Dysglycemia was not generally associated with diabetes mellitus per se. Nevertheless, patients with more comorbidities, especially those with chronic kidney disease, receiving antidiabetics and/or steroids had more glycemic events when treated with fluoroquinolones.

Conclusion

Moxifloxacin was found to be associated the most and ciprofloxacin the least with dysglycemia. fluoroquinolones must be used with great caution among diabetic patients who have comorbidities and are receiving antidiabetics and/or steroids. Further evidence is required from studies on neuropathy caused by fluoroquinolones.

Preoperative Management of Endocrine, Hormonal, and Urologic Medications: Society for Perioperative Assessment and Quality Improvement (SPAQI) Consensus Statement

Perioperative medical management is challenging due to the rising complexity of patients presenting for surgical procedures. A key part of preoperative optimization is appropriate management of long-term medications, yet guidelines and consensus statements for perioperative medication management are lacking. Available resources utilize the recommendations derived from individual studies and do not include a multidisciplinary focus or formal consensus. The Society for Perioperative Assessment and Quality Improvement (SPAQI) identified a lack of authoritative clinical guidance as an opportunity to utilize its multidisciplinary membership to improve evidence-based perioperative care. SPAQI seeks to provide guidance on perioperative medication management that synthesizes available literature with expert consensus. The aim of this Consensus Statement is to provide practical guidance on the preoperative management of endocrine, hormonal, and urologic medications. A panel of experts with anesthesiology, perioperative medicine, hospital medicine, general internal medicine, and medical specialty experience was drawn together and identified the common medications in each of these categories. The authors then utilized a modified Delphi approach to critically review the literature and generate consensus recommendations.

Fluoroquinolones suppress gluconeogenesis by inhibiting fructose 1,6-bisphosphatase in primary monkey hepatocytes

Dysglycemia is one of the most serious adverse events associated with the clinical use of certain fluoroquinolones. The purpose of this study was to investigate the effects of the representative fluoroquinolones moxifloxacin and gatifloxacin on hepatic gluconeogenesis using primary monkey hepatocytes. Glucose production was induced after the cells were incubated for 4 h with 10 mM sodium lactate and 1 mM sodium pyruvate as gluconeogenic substrates. Under these conditions, moxifloxacin and gatifloxacin dose-dependently suppressed gluconeogenesis at concentrations of 100 μM or higher. Transcriptome analysis of rate-limiting enzymes involved in hepatic gluconeogenesis revealed that moxifloxacin and gatifloxacin at a concentration of 1000 μM did not affect the expression of key gluconeogenic enzymes such as phosphoenolpyruvate carboxykinase, glucose 6-phosphatase, and fructose 1,6-bisphosphatase. Furthermore, metabolome analysis, in vitro glucose production assay using additional gluconeogenic substrates, and fructose 1,6-bisphosphatase assay using the cell extracts showed that fluoroquinolones enzymatically suppressed hepatic gluconeogenesis by inhibiting fructose 1,6-bisphosphatase. These inhibitory effects may involve in the clinically relevant dysglycemia associated with fluoroquinolones in human.

Hypoglycemia Associated with Antibiotics Alone and in Combination with Sulfonylureas and Meglitinides: An Epidemiologic Surveillance Study of the FDA Adverse Event Reporting System (FAERS)

INTRODUCTION

Fluoroquinolones, clarithromycin, linezolid, tigecycline, cefditoren, doxycycline, and trimethoprim-sulfamethoxazole are known to be associated with hypoglycemia, but few studies have considered concomitant glucose-lowering medications.

OBJECTIVE

The objective of this study was to evaluate the association between hypoglycemia and antibiotics using the US Food and Drug Administration Adverse Event Reporting System (FAERS), while accounting for concomitant glucose-lowering medications including sulfonylureas and meglitinides.

METHODS

FAERS reports from 1 January 2004 to 31 December 2017 were included in the study. Reporting odds ratios (RORs) and corresponding 95% confidence intervals (CIs) for the association between antibiotics and hypoglycemia were calculated. An association was considered to be statistically significant when the lower limit of the 95% CI was > 1.0.

RESULTS

A total of 2,334,959 reports (including 18,466 hypoglycemia reports) were considered, after inclusion criteria were applied. Statistically significant hypoglycemia RORs (95% CI) for antibiotics were: cefditoren 14.03 (8.93-22.03), tigecycline 3.32 (1.95-5.65), clarithromycin 2.41 (1.89-3.08), ertapenem 2.07 (1.14-3.75), moxifloxacin 2.06 (1.59-2.65), levofloxacin 1.66 (1.37-2.01), and linezolid 1.54 (1.07-2.20). After adjusting for concomitant sulfonylureas and meglitinides, the following antibiotics were still significantly associated with hypoglycemia: cefditoren 14.25 (9.08-22.39), tigecycline 3.34 (1.96-5.68), ertapenem 1.93 (1.03-3.60), and clarithromycin 1.56 (1.15-2.11).

CONCLUSION

In many patients, antibiotics, including fluoroquinolones, are associated with hypoglycemia when they are also taking sulfonylureas or meglitinides. Cefditoren, tigecycline, ertapenem, and clarithromycin are associated with hypoglycemia even if not taken with sulfonylureas or meglitinides. The association between ertapenem and hypoglycemia has not been previously reported.

Optimizing Drug Therapies in Patients with COPD in the US Nursing Home Setting

Chronic obstructive pulmonary disease (COPD) can be a disabling disease, and the impact on older adults is particularly evident in the nursing home setting. Chronic obstructive pulmonary disease is present in about 20% of nursing home residents, most often in women, and accounts for significant healthcare utilization including acute care visits for exacerbations and pneumonia, as well as worsening heart disease and diabetes mellitus. The emphasis on hospital readmissions is particularly important in nursing homes where institutions have quality measures that have financial implications. Optimizing drug therapies in individuals with COPD involves choosing medications that not only improve symptoms, but also decrease the risk of exacerbations. Optimizing the treatment of comorbidities such as heart disease, infections, and diabetes that may affect COPD outcomes is also an important consideration. Depending on the nursing home setting and the patient, the options for optimizing COPD drug therapies may be limited owing to patient-related factors such as cognition and physical impairment or available resources, primarily reimbursement-related issues. Choosing the best drug therapy for COPD in older adults is limited by the difficulty in assessing respiratory symptoms using standardized assessment tools and potentially decreased inspiratory ability of frail individuals. Because of cognitive and physical impediments, ensuring optimal delivery of inhaled medications into the lungs has significant challenges. Long-acting bronchodilators, inhaled corticosteroids, and roflumilast decrease the risk of exacerbations, although inhaled corticosteroids should be used judiciously in this population because of the risk of pneumonia and oropharyngeal side effects. Treatment of COPD exacerbations should occur early and consideration should be made to the benefits and risks of systemic corticosteroids and antibiotics. Clinical research in the COPD population in nursing homes is clearly lacking, and ripe for discovery of effective management strategies.

Safety of Delafloxacin: Focus on Adverse Events of Special Interest

Background

Fluoroquinolones have been widely used for a variety of Gram-positive and Gram-negative infections, and by 2002 they had become the most commonly prescribed class of antibiotics for adults in the United States. With widespread use, the class has become associated with a range of adverse events. Delafloxacin is a fluoroquinolone approved in the United States for the treatment of adults with acute bacterial skin and skin structure infections (ABSSSIs). Delafloxacin is differentiated from other fluoroquinolones due to structural differences and in its activity against methicillin-resistant Staphylococcus aureus, including quinolone-resistant strains. This paper reviews the safety profile of delafloxacin across clinical studies with an emphasis on the incidence of adverse events of special interest that are associated with fluoroquinolones.

Methods

Data from 2 completed phase III studies of delafloxacin for the treatment of ABSSSIs were pooled and are the primary focus of this paper. Additional support from the full safety analysis set (30 completed phase I to phase III clinical studies) is included where applicable.

Results

Fewer patients in the pooled delafloxacin group had AESIs than in the comparator group (7.0% vs 9.2%, respectively). Delafloxacin had a low rate of discontinuations due to treatment-related adverse events (<1%). Serious adverse events occurred at similar rates in patients treated with delafloxacin vs comparators.

Conclusions

Serious adverse events occurred at similar rates in patients treated with delafloxacin vs nonquinolone comparators used to treat ABSSSIs.

Clinicaltrials.gov identifier

NCT01984684 and NCT01811732

Biomedical Informatics Approaches to Identifying Drug-Drug Interactions: Application to Insulin Secretagogues

BACKGROUND

Drug-drug interactions with insulin secretagogues are associated with increased risk of serious hypoglycemia in patients with type 2 diabetes. We aimed to systematically screen for drugs that interact with the five most commonly used secretagogues-glipizide, glyburide, glimepiride, repaglinide, and nateglinide-to cause serious hypoglycemia.

METHODS

We screened 400 drugs frequently coprescribed with the secretagogues as candidate interacting precipitants. We first predicted the drug-drug interaction potential based on the pharmacokinetics of each secretagogue-precipitant pair. We then performed pharmacoepidemiologic screening for each secretagogue of interest, and for metformin as a negative control, using an administrative claims database and the self-controlled case series design. The overall rate ratios (RRs) and those for four predefined risk periods were estimated using Poisson regression. The RRs were adjusted for multiple estimation using semi-Bayes method, and then adjusted for metformin results to distinguish native effects of the precipitant from a drug-drug interaction.

RESULTS

We predicted 34 pharmacokinetic drug-drug interactions with the secretagogues, nine moderate and 25 weak. There were 140 and 61 secretagogue-precipitant pairs associated with increased rates of serious hypoglycemia before and after the metformin adjustment, respectively. The results from pharmacokinetic prediction correlated poorly with those from pharmacoepidemiologic screening.

CONCLUSIONS

The self-controlled case series design has the potential to be widely applicable to screening for drug-drug interactions that lead to adverse outcomes identifiable in healthcare databases. Coupling pharmacokinetic prediction with pharmacoepidemiologic screening did not notably improve the ability to identify drug-drug interactions in this case.

Risk of gastrointestinal perforation in patients taking oral fluoroquinolone therapy: An analysis of nationally representative cohort

Background

Fluoroquinolone is a commonly prescribed antimicrobial agent, and up to 20% of its users registers adverse gastroenterological symptoms. We aimed to evaluate the association between use of fluoroquinolone and gastrointestinal tract perforation.

Methods

We conducted a nested case-control study on a national health insurance claims database between 1998 and 2011. The use of fluoroquinolones was classified into current (< 60 days), past (61–365 days prior to the index date) and any prior year use of fluoroquinolones. We used the conditional logistic regression model to estimate rate ratios (RRs), adjusting or matching by a disease risk score (DRS).

Results

We identified a cohort of 17,510 individuals diagnosed with gastrointestinal perforation and matched them to 1,751,000 controls. Current use of fluoroquinolone was associated with the greatest increase in risk of gastrointestinal perforations after DRS score adjustment (RR, 1.90; 95% CI, 1.62–2.22). The risk of gastrointestinal perforation was attenuated for past (RR, 1.33; 95% CI, 1.20–1.47) and any prior year use (RR, 1.46; 95% CI, 1.34–1.59). To gain insights into whether the observed association can be explained by unmeasured confounder, we compared the risk of gastrointestinal perforation between fluoroquinolone and macrolide. Use of macrolide, an active comparator, was not associated with a significant increased risk of gastrointestinal perforation (RR, 1.11, 95%CI, 0.15–7.99). Sensitivity analysis focusing on perforation requiring in-hospital procedures also demonstrated an increased risk associated with current use. To mitigate selection bias, we have also excluded people who have never used fluoroquinolone before or people with infectious colitis, enteritis or gastroenteritis. In both of the analysis, a higher risk of gastrointestinal perforation was still associated with the use of fluoroquinolone.

Conclusions

We found that use of fluoroquinolones was associated with a non-negligible increased risk of gastrointestinal perforation, and physicians should be aware of this possible association.

Effect of antibiotics on gut microbiota, glucose metabolism and body weight regulation: a review of the literature

Gut bacteria are involved in a number of host metabolic processes and have been implicated in the development of obesity and type 2 diabetes in humans. The use of antibiotics changes the composition of the gut microbiota and there is accumulating evidence from observational studies for an association between exposure to antibiotics and development of obesity and type 2 diabetes. In the present paper, we review human studies examining the effects of antibiotics on body weight regulation and glucose metabolism and discuss whether the observed findings may relate to alterations in the composition and function of the gut microbiota.

Moxifloxacin and gatifloxacin for initial therapy of tuberculosis: a meta-analysis of randomized clinical trials

Moxifloxacin (MOX) and gatifloxacin (GAT) have exhibited promising mycobactericidal activity, and a number of clinical trials have been conducted in recent decades to compare the treatment efficacy of MOX-containing and/or GAT-containing regimens with the standard regimen. The aim of this meta-analysis for clinical trials of MOX- or GAT-containing regimens was to evaluate their treatment efficacy and safety in initial therapy for drug-sensitive tuberculosis (TB). Databases were searched for randomized controlled trials, and nine studies with 6980 patients were included. We found that fluoroquinolone substitution for isoniazid or ethambutol in short-course regimens might result in more frequent unfavorable treatment outcomes compared with the standard regimen—in particular, an increased incidence of relapse. In a per-protocol analysis, MOX-containing regimens had slightly higher rates of sputum culture conversion at two months than the standard regimen (RR 1.08, 95% CI 1.04–1.11, P <0.001); there was no significant difference in the rate of sputum conversion between the GAT-containing regimens and the standard regimen (RR 1.13, 95% CI 0.96–1.33, P = 0.13). There were no significant differences in the incidence of death from any cause, including TB, nor were there serious adverse events between the MOX- or GAT-containing regimens and the standard regimen. In conclusion, MOX or GAT might not have the ability to shorten treatment duration in the initial therapy for tuberculosis despite the non-inferiority or even slightly better efficacy in the early phase of treatment compared with the standard regimen. Furthermore, it is safe to include MOX or GAT in initial TB treatment.

Life-threatening metabolic coma caused by levofloxacin

Patients with diabetes mellitus are often susceptible to hypoglycemic episodes while on therapy. Most of these are attributed to inappropriate dosing of hypoglycemic agents, dietary indiscretion, or acute illness. Medications being used concomitantly should be reviewed closely when the etiology of hypoglycemia is unclear. A fifty-six-year-old woman with a history of diabetes mellitus (on metformin monotherapy) was found unresponsive at home. Her fingerstick glucose was 15 mg/dL for which she received 50% dextrose intravenously. The patient never had any previous documented hypoglycemic episodes. She had recently been diagnosed with pneumonia and was prescribed oral levofloxacin therapy. The patient had taken 4 doses of levofloxacin before the onset of hypoglycemia. These episodes recurred over the next 2 days needing close intensive care unit monitoring, dextrose infusion, and glucagon administration. Basic blood/urine investigations, cortisol and thyroid profile were normal except for low blood glucose and renal insufficiency (serum creatinine 1.4 mg/dL and creatinine clearance 42 mL/min). HbA1c was 6.8% (4.4%-6.4%), insulin 51.3 μU/mL (2.6-24.9 μU/mL), IGF-1 301 ng/mL (27-223 ng/mL), and C peptide 9.3 ng/mL (0.8-3.5 ng/mL). These levels were elevated but were deemed nondiagnostic because of fluctuating glucose values after glucagon administration. A blood screen for sulfonylureas and metaglinides was negative. A seventy-two-hour fast was performed to rule out hyperinsulinemic hypoglycemic syndromes; however, blood glucose values remained consistently above 120 mg/dL during this period. Thus, after exclusion of other causes, we utilized the adverse drug reaction probability scale and concluded that hypoglycemia was probably related to recent use of levofloxacin.

Dysglycemia associated with quinolones

Antimicrobial therapy is well known to be associated with fluctuations of blood glucose levels. This review aims at exploring the association between glycemic fluctuations and antibiotics mainly focusing on quinolones. Quinolones are associated with hypoglycemia and hyperglycemia. Several mechanism are proposed to explain this causality.

Evaluation of the appropriate use of commonly prescribed fluoroquinolones and the risk of dysglycemia

Background

Fluoroquinolones are among the most widely prescribed antibiotics. However, concerns about increasing resistant microorganisms and the risk of dysglycemia associated with the use of these agents have emerged.

Objective

The primary objective of the study was to evaluate the appropriate use of commonly prescribed fluoroquinolones, including appropriate indication, dose, dose adjustment in renal impairment, and duration of treatment. The secondary objective was to investigate the dysglycemic effect of fluoroquinolone use (hypoglycemia and/or hyperglycemia) in diabetic and nondiabetic patients.

Methods

A prospective observational study at a teaching hospital in Lebanon was conducted over a 6-month period. A total of 118 patients receiving broad-spectrum fluoroquinolones (levofloxacin, ciprofloxacin, and moxifloxacin) were identified. Patients were mainly recruited from internal medicine floors and intensive care units.

Results

The final percentage for the appropriate indication, dose, and duration of fluoroquinolone therapy was 93.2%, 74.6%, and 57.6%, respectively. A total of 57.1% of the patients did not receive the appropriate dose adjustment according to their level of renal impairment. In addition, dysglycemia occurred in both diabetic and nondiabetic patients. Dysglycemia was more frequently encountered with ciprofloxacin (50.0%), followed by levofloxacin (42.4%) and moxifloxacin (7.6%). Hyperglycemia was more common than hypoglycemia in all groups. The highest incidence of hyperglycemia occurred with levofloxacin (70.0%), followed by ciprofloxacin (39.0%) and moxifloxacin (33.3%). In contrast, hypoglycemia did not occur in the ciprofloxacin group, but it was more common with moxifloxacin (11.1%) and levofloxacin (6.0%).

Conclusion

The major clinical interventions for the future will adjust the dose and duration of therapy with commonly prescribed fluoroquinolones. The incidence of hypoglycemia was less common than hyperglycemia.

A four-month gatifloxacin-containing regimen for treating tuberculosis

BACKGROUND

Shortening the course of treatment for tuberculosis would be a major improvement for case management and disease control. This phase 3 trial assessed the efficacy and safety of a 4-month gatifloxacin-containing regimen for treating rifampin-sensitive pulmonary tuberculosis.

METHODS

We conducted a noninferiority, randomized, open-label, controlled trial involving patients 18 to 65 years of age with smear-positive, rifampin-sensitive, newly diagnosed pulmonary tuberculosis in five sub-Saharan African countries. A standard 6-month regimen that included ethambutol during the 2-month intensive phase was compared with a 4-month regimen in which gatifloxacin (400 mg per day) was substituted for ethambutol during the intensive phase and was continued, along with rifampin and isoniazid, during the continuation phase. The primary efficacy end point was an unfavorable outcome (treatment failure, recurrence, or death or study dropout during treatment) measured 24 months after the end of treatment, with a noninferiority margin of 6 percentage points, adjusted for country.

RESULTS

A total of 1836 patients were assigned to the 4-month regimen (experimental group) or the standard regimen (control group). Baseline characteristics were well balanced between the groups. At 24 months after the end of treatment, the adjusted difference in the risk of an unfavorable outcome (experimental group [21.0%] minus control group [17.2%]) in the modified intention-to-treat population (1356 patients) was 3.5 percentage points (95% confidence interval, -0.7 to 7.7). There was heterogeneity across countries (P=0.02 for interaction, with differences in the rate of an unfavorable outcome ranging from -5.4 percentage points in Guinea to 12.3 percentage points in Senegal) and in baseline cavitary status (P=0.04 for interaction) and body-mass index (P=0.10 for interaction). The standard regimen, as compared with the 4-month regimen, was associated with a higher dropout rate during treatment (5.0% vs. 2.7%) and more treatment failures (2.4% vs. 1.7%) but fewer recurrences (7.1% vs. 14.6%). There was no evidence of increased risks of prolongation of the QT interval or dysglycemia with the 4-month regimen.

CONCLUSIONS

Noninferiority of the 4-month regimen to the standard regimen with respect to the primary efficacy end point was not shown. (Funded by the Special Program for Research and Training in Tropical Diseases and others; ClinicalTrials.gov number, NCT00216385.).

Pharmacotherapy for Hyperglycemia in Noncritically Ill Hospitalized Patients

In Brief Hyperglycemia in the hospital setting affects 38-46% of noncritically ill hospitalized patients. Evidence from observational studies indicates that inpatient hyperglycemia, in patients with and without diabetes, is associated with increased risks of complications and mortality. Substantial evidence indicates that correction of hyperglycemia through insulin administration reduces hospital complications and mortality in critically ill patients, as well as in general medicine and surgery patients. This article provides a review of the evidence on the different therapies available for hyperglycemia management in noncritically ill hospitalized patients.

Effect of fluoroquinolones on mitochondrial function in pancreatic beta cells

Hyper- and hypoglycaemias are known side effects of fluoroquinolone antibiotics, resulting in a number of fatalities. Fluoroquinolone-induced hypoglycaemias are due to stimulated insulin release by the inhibition of the KATP channel activity of the beta cell. Recently, it was found that fluoroquinolones were much less effective on metabolically intact beta cells than on open cell preparations. Thus the intracellular effects of gatifloxacin, moxifloxacin and ciprofloxacin were investigated by measuring NAD(P)H- and FAD-autofluorescence, the mitochondrial membrane potential, and the adenine nucleotide content of isolated pancreatic islets and beta cells. 100 μM of moxifloxacin abolished the NAD(P)H increase elicited by 20mM glucose, while gatifloxacin diminished it and ciprofloxacin had no significant effect. This pattern was also seen with islets from SUR1 Ko mice, which have no functional KATP channels. Moxifloxacin also diminished the glucose-induced decrease of FAD-fluorescence, which reflects the intramitochondrial production of reducing equivalents. Moxifloxacin, but not ciprofloxacin or gatifloxacin significantly reduced the effect of 20mM glucose on the ATP/ADP ratio. The mitochondrial hyperpolarization caused by 20mM glucose was partially antagonized by moxifloxacin, but not by ciprofloxacin or gatifloxacin. Ultrastructural analyses after 20 h tissue culture showed that all three compounds (at 10 and 100 μM) diminished the number of insulin secretory granules and that gatifloxacin and ciprofloxacin, but not moxifloxacin induced fission/fusion configurations of the beta cell mitochondria. In conclusion, fluoroquinolones affect the function of the mitochondria in pancreatic beta cells which may diminish the insulinotropic effect of KATP channel closure and contribute to the hyperglycaemic episodes.

Risk of severe dysglycemia among diabetic patients receiving levofloxacin, ciprofloxacin, or moxifloxacin in Taiwan

BACKGROUND

Observational studies and fatal case reports raise concern about the safety of severe dysglycemia associated with fluoroquinolone use. The objective of this study was to assess the risk of severe dysglycemia among diabetic patients who received different fluoroquinolones.

METHODS

In a population-based inception cohort study of diabetic patients covering the period from January 2006 to November 2007, outpatient new users of levofloxacin, ciprofloxacin, moxifloxacin, cephalosporins, and macrolides orally were identified. Study events were defined as emergency department visits or hospitalization for dysglycemia within 30 days following the initiation of antibiotic therapy. Results were analyzed with adjusted multinomial propensity score.

RESULTS

A total of 78 433 diabetic patients receiving the antibiotics of interest were included in the study. The absolute risk of hyperglycemia per 1000 persons was 6.9 for moxifloxacin and 1.6 for macrolides. In contrast, the risk of hypoglycemia was 10.0 for moxifloxacin and 3.7 for macrolides. The adjusted odds ratios (AORs) and 95% confidence intervals (CIs) of levofloxacin, ciprofloxacin, and moxifloxacin compared with macrolides were 1.75 (1.12-2.73), 1.87 (1.20-2.93), and 2.48 (1.50-4.12), respectively, for hyperglycemia and 1.79 (1.33-2.42), 1.46 (1.07-2.00), and 2.13 (1.44-3.14), respectively, for hypoglycemia. Patients taking moxifloxacin faced a significantly higher risk of hypoglycemia than those receiving ciprofloxacin. A significant increase in the risk of hypoglycemia was also observed among patients receiving moxifloxacin concomitantly with insulin (AOR, 2.28; 95% CI, 1.22-4.24).

CONCLUSIONS

Diabetics using oral fluoroquinolones faced greater risk of severe dysglycemia. The risk of hypoglycemia varied according to the type of fluoroquinolone administered, and was most commonly associated with moxifloxacin.

The effect of levofloxacin and moxifloxacin on cardiovascular functions of rats with streptozotocin-induced diabetes

Fluoroquinolone antibiotics cause rare, but clinically important, adverse events including hyperglycaemia and hypoglycaemia. The present study focuses on the possible effect of levofloxacin and moxifloxacin on the cardiovascular functions of rats with type I diabetes. Both antibiotics caused bradycardia. Levofloxacin but not moxifloxacin caused hypoglycaemia in diabetic rats and an increase in amplitude of the ST segment revealed by electrocardiogram (ECG) analysis of isolated hearts. In pressurized mesenteric arteries, levofloxacin did not affect the endothelium-derived hyperpolarising factor (EDHF) pathway or its main components, the small-conductance Ca(2+) activated potassium (SK(Ca)) and intermediate-conductance Ca(2+) activated potassium (IK(Ca)) channels. In moxifloxacin-treated rats, an increase in the EDHF response was observed, which was largely attributed to SK(Ca)-activation. In conclusion, levofloxacin and moxifloxacin use appeared to vary but with no evidence of impairment of the cardiovascular function. However, it is still possible that these antibiotics may produce different effects if there are co-morbidities and therefore their use must be with care.

Cardiovascular and metabolic safety profiles of the fluoroquinolones

INTRODUCTION

Certain fluoroquinolones share similar indications of use. A comparison among Cardiovascular and metabolic (i.e., dysglycemia) safety profiles of the fluoroquinolones might be particularly useful for the prescribers' decision-making process as well as to hypothesize future researcher purposes.

AREAS COVERED

A literature search was conducted using keywords apt to identify information on safety profile of the fluoroquinolones. Publications concerned with descriptive and etiological surveys were manually reviewed.

EXPERT OPINION

Cardiac alterations and blood glucose impairments might be associated with any fluoroquinolone. However, the benefit/risk profile of these agents could be stratified for the single compounds. Several predisposing factors, such as diabetes, heart illnesses and their related pharmacotherapies, might exacerbate the risk of potentially serious adverse events. In this context, the opportunity of the more appropriate choice among different fluoroquinolones could be applicable.

Drug-induced hypoglycaemia: an update

Drugs are the most frequent cause of hypoglycaemia in adults. Although hypoglycaemia is a well known adverse effect of antidiabetic agents, it may occasionally develop in the course of treatment with drugs used in everyday clinical practice, including NSAIDs, analgesics, antibacterials, antimalarials, antiarrhythmics, antidepressants and other miscellaneous agents. They induce hypoglycaemia by stimulating insulin release, reducing insulin clearance or interfering with glucose metabolism. Several drugs may also potentiate the hypoglycaemic effect of antidiabetic agents. Administration of these agents to individuals with diabetes mellitus is of most concern. Many of these drugs, and depending on clinical setting, may also induce hyperglycaemia. Drug-induced hepatotoxicity and nephrotoxicity may lead in certain circumstances to hypoglycaemia. Some drugs may also induce hypoglycaemia by causing pancreatitis. Drug-induced hypoglycaemia is usually mild but may be severe. Effective clinical management can be handled through awareness of this drug-induced adverse effect on blood glucose levels. Herein, we review pertinent clinical information on the incidence of drug-induced hypoglycaemia and discuss the underlying pathophysiological mechanisms, and prevention and management.

Glimepiride-Induced Hypoglycemia with Ciprofloxacin, Metronidazole, and Acute Kidney Injury

A 79-year-old white male presented to the emergency room with altered mental status and a blood glucose of 28 mg/dL. He was taking glimepiride 1 mg by mouth daily prior to admission and had recently been prescribed ciprofloxacin and metronidazole for diverticulitis. The patient was also found to have acute-on-chronic renal failure upon presentation. Escalated dextrose infusion with repeated doses of D50W and glucagon failed to sustain his blood glucose, which remained in the range of 30 to 50 mg/dL. Salvage treatment with intravenous octreotide was implemented successfully; only one dose of D50W was required after octreotide initiation and blood glucose normalized within several hours. In the presence of this patient's complex medication therapy, we explore the contributing causes of hypoglycemia. Fluoroquinolones are widely associated with dysglycemias, particularly in diabetic patients receiving hypoglycemic agents. Similarly, renal insufficiency has been implicated to precipitate hypoglycemia with sulfonylureas, with dosage adjustment being required almost class-wide. We also recognize a theoretical drug interaction mediated by metronidazole-induced CYP 2C9 inhibition of glimepiride metabolism. Sulfonylurea-induced hypoglycemia can be serious and refractory to traditional therapy and can be exacerbated by multiple factors, such as drug interactions or impaired renal function. In the era of complex medication therapy for patient populations with multiple disease states, we present a severe episode of glimepiride-induced hypoglycemia with multiple causative factors.

Safety profile of the fluoroquinolones: analysis of adverse drug reactions in relation to prescription data using four regional pharmacovigilance databases in Italy

BACKGROUND

Fluoroquinolones are widely used both in primary care and in hospital settings. Since the last comparison performed in Italy on the safety profiles of different fluoroquinolones, a new molecule, prulifloxacin, has been introduced into the market and several warnings concerning this class of drugs have been released. The aim of this study was to reassess the safety profiles of fluoroquinolones using the database of the Italian Interregional Group of Pharmacovigilance (IGP) and the administrative data of fluoroquinolone prescriptions.

METHODS

All adverse drug reactions (ADRs) reported in four Italian regions (Lombardy, Veneto, Emilia Romagna and Tuscany) were retrieved from the IGP database. Consumption data (defined daily dose [DDD]/1000 inhabitants/day) were used as denominators. Both single reports and all ADRs (classified by System Organ Classes and MedDRA Preferred Term [PT]) due to fluoroquinolones were considered as numerators of each analysis, comparing two periods (2005 vs 2006). All fluoroquinolones with at least ten reports per year were included in the analysis.

RESULTS

On the basis of 272 reports (532 single ADRs or PTs), patients did not show any statistically significant differences between 2005 and 2006 in terms of sex, age and number of concurrent medications. After adjustment for drug consumption, moxifloxacin showed the highest reporting rate (84.6 reports/DDD/1000 inhabitants/day; 15.4 serious reports/DDD/1000 inhabitants/day) followed by prulifloxacin (72.2; 22.2 serious) and levofloxacin (55.3; 30.6 serious) in 2005. An increment of ADR/report rates was observed over the 2 years for all fluoroquinolones except prulifloxacin, which had the lowest ADR reporting rate in 2006 (25.0; 12.5 serious). In 2006, the rate of serious ADRs associated with prulifloxacin was lower than with ciprofloxacin, while in 2005 serious events were almost equal for both compounds (55.6 vs 47.6 serious ADRs/DDD/1000 inhabitants/day). Ciprofloxacin showed the highest proportion of cutaneous PTs (e.g. rash, exanthema). Tendinopathies were mainly due to levofloxacin.

CONCLUSIONS

These data suggest that different fluoroquinolones are characterized by different rates and types of ADRs. Among them, prulifloxacin was associated with more ADRs than other fluoroquinolones in 2005 but with fewer ADRs in 2006, when its consumption increased. Although these findings may represent an encouraging perspective towards a more appropriate use of fluoroquinolones because of their individual safety profiles, further pharmacoepidemiological studies must be performed to substantiate these results.

Drug-induced endocrine disorders in the intensive care unit

The neuroendocrine response to critical illness is key to the maintenance of homeostasis. Many of the drugs administered routinely in the intensive care unit significantly impact the neuroendocrine system. These agents can disrupt the hypothalamic-pituitary-adrenal axis, cause thyroid abnormalities, and result in dysglycemia. Herein, we review major drug-induced endocrine disorders and highlight some of the controversies that remain in this area. We also discuss some of the more rare drug-induced syndromes that have been described in the intensive care unit. Drugs that may result in an intensive care unit admission secondary to an endocrine-related adverse event are also included. Unfortunately, very few studies have systematically addressed drug-induced endocrine disorders in the critically ill. Timely identification and appropriate management of drug-induced endocrine adverse events may potentially improve outcomes in the critically ill. However, more research is needed to fully understand the impact of medications on endocrine function in the intensive care unit.

Empiric therapy for gram-negative pathogens in nosocomial and health care-associated pneumonia: starting with the end in mind

Nosocomial pneumonia is a major cause of morbidity and mortality for hospitalized patients. Antimicrobial resistance is increasing, creating a strain between ensuring the provision of adequate empiric therapy and slowing the development of antimicrobial resistance. Excessive antimicrobial therapy places patients are at greater risk of drug interactions, adverse events, and superinfections. Ways to maximize adequate empiric therapy include (1) categorizing each patient's risk of being infected with a multidrug-resistant pathogen and knowledge of local susceptibility patterns, (2) de-escalating antimicrobial therapy to decrease the rates of superinfections such as Clostridium difficile, and (3) limiting the duration of therapy to decrease the likelihood of adverse events, drug interactions, and antimicrobial resistance. Pharmacodynamically enhanced dosing regimens also have the potential to improve clinical outcomes and slow the development of antimicrobial resistance. Drugs whose killing is optimized by the percentage time above the minimum inhibitory concentration (MIC), such as beta-lactams, can be given by continuous or extended infusion to provide superior pharmacodynamic (PD) target attainment rates compared with traditional regimens. Drugs whose killing is optimized with a high-peak plasma concentration to MIC ratio (eg, aminoglycosides) should be administered once daily to maximize the likelihood of achieve optimal target attainment rates. Drugs whose killing is optimized by the ratio of the area under the curve (AUC) to MIC ratio (eg, fluoroquinolones) depend on the total daily dose as opposed to the dosing schedule or infusion time. Determining the optimal drug dosing schedules for obese patients remains critical because these patients have may have significantly increased volumes of distribution and clearance rates compared to normal weight patients. Optimizing the use of current antimicrobials is paramount to ensure quality treatment options are available, given the lack of gram-negative antimicrobials in the pipeline.

Safety profile of the fluoroquinolones: focus on levofloxacin

The fluoroquinolone class of antibacterial agents are among the most frequently prescribed drugs, with utility in a broad range of bacterial infections. Although very useful agents, the fluoroquinolones as a class are associated with a number of adverse events, some with considerable clinical significance. In the past 15-20 years, tolerability concerns have led to restrictions on the use of the fluoroquinolones and, in some instances, the withdrawal of agents from the market. This review focuses on the safety and tolerability of levofloxacin, a third-generation fluoroquinolone, relative to other fluoroquinolones. A literature search was performed of the MEDLINE database encompassing the dates 1980-2009, using as keywords the drug names levofloxacin and concurrently marketed fluoroquinolones combined with the words 'safety', 'adverse effect' or 'adverse drug reaction', or the name of the specific adverse effect. Adverse events commonly associated with the fluoroquinolones include gastrointestinal and CNS toxicity (most frequently headache and dizziness), as well as other adverse events including ECG abnormalities (for example QT interval prolongation), disrupted glucose metabolism, phototoxicity, tendon and joint disorders, hypersensitivity and skin disorders, and hepatic toxicity. Package inserts for the fluoroquinolones in Europe and the US contain warnings regarding these risks. US package inserts also carry 'black-box' warnings regarding the risk of tendon rupture and joint disorders with these agents; however, there is a substantial body of evidence to indicate that there are marked differences in the tolerability profiles of the individual agents within the fluoroquinolone class. These differences may be explained, at least in part, by structural differences: all fluoroquinolones share a basic quinolone core, with differences in specific side chains underlying the adverse event relationships. Furthermore, many of the fluoroquinolone-associated adverse effects and toxicities occur more frequently in patients with pre-existing risk factors, or in certain subpopulations. Notably, package inserts for the fluoroquinolones carry warnings regarding use in the elderly, paediatric patients and patients with pre-existing, or factors predisposing to, seizure disorders. Because of this, many adverse reactions with these agents could be prevented by improving patient screening and education. The recent withdrawal of gatifloxacin due to dysglycaemia makes it timely to review the safety and tolerability of the individual agents in this class. Overall, it appears that levofloxacin is relatively well tolerated, with low rates of clinically important adverse events such as CNS toxicity, cardiovascular toxicity and dysglycaemia.

Statement by an American Association of Clinical Endocrinologists/American College of Endocrinology consensus panel on type 2 diabetes mellitus: an algorithm for glycemic control

This report presents an algorithm to assist primary care physicians, endocrinologists, and others in the management of adult, nonpregnant patients with type 2 diabetes mellitus. In order to minimize the risk of diabetes-related complications, the goal of therapy is to achieve a hemoglobin A1c (A1C) of 6.5% or less, with recognition of the need for individualization to minimize the risks of hypoglycemia. We provide therapeutic pathways stratified on the basis of current levels of A1C, whether the patient is receiving treatment or is drug naïve. We consider monotherapy, dual therapy, and triple therapy, including 8 major classes of medications (biguanides, dipeptidyl-peptidase-4 inhibitors, incretin mimetics, thiazolidinediones, alpha-glucosidase inhibitors, sulfonylureas, meglitinides, and bile acid sequestrants) and insulin therapy (basal, premixed, and multiple daily injections), with or without orally administered medications. We prioritize choices of medications according to safety, risk of hypoglycemia, efficacy, simplicity, anticipated degree of patient adherence, and cost of medications. We recommend only combinations of medications approved by the US Food and Drug Administration that provide complementary mechanisms of action. It is essential to monitor therapy with A1C and self-monitoring of blood glucose and to adjust or advance therapy frequently (every 2 to 3 months) if the appropriate goal for each patient has not been achieved. We provide a flow-chart and table summarizing the major considerations. This algorithm represents a consensus of 14 highly experienced clinicians, clinical researchers, practitioners, and academicians and is based on the American Association of Clinical Endocrinologists/American College of Endocrinology Diabetes Guidelines and the recent medical literature.

Risk factors for hyperglycemia in hospitalized adults receiving gatifloxacin: a retrospective, nested case-controlled analysis

BACKGROUND

The prevalence of glucose abnormalities has been reported to be greater in hospitalized patients receiving gatifloxacin than in patients receiving ceftriaxone.

OBJECTIVE

The purpose of the current study was to identify risk factors for hyperglycemia in hospitalized patients receiving gatifloxacin.

METHODS

This retrospective, nested case-controlled study was conducted in 69 patients and 69 controls in 2 nonteaching hospitals in Houston, Texas. Classification and regression tree (CART) analysis was conducted to identify break points in continuous variables. Univariate and multivariate logistic regression analyses were also performed.

RESULTS

A total of 138 patients (mean [SD] age, 68.3 [17.3] years; weight, 77.4 [21.1] kg; sex, women/ men, 69.6%/30.4%; race [Hispanic, 58.3%; white, 28.5%; black, 9.2%; other, 4.0%]) were identified. Patients who developed hyperglycemia (blood glucose level > 200 mg/dL) within 72 hours of gatifloxacin administration (cases) were matched 1:1 with patients who received gatifloxacin for > or = 5 days and did not experience hyperglycemia during treatment and for 3 days after the end of treatment (controls). In univariate analysis, cases were more likely than controls to have diabetes (89.9% vs 13.0%; P < 0.001), have a decreased mean (SD) creatinine clearance (CrCl) (53.8 [36.8] vs 69.2 [45.3] mL/min; P = 0.025), be located in the intensive care unit at the time of the event (20.3% vs 7.2%; P = 0.02), have received gatifloxacin doses higher than recommended based on renal function (> 200 mg/d when CrCl < 40 mL/min) (25/69 [36.2%] vs 9/69 [13.0%]), have leukocytosis (mean [SD] white blood cell [WBC] count, 15.5 [7.4] vs 12.8 [6.2] cells/mm3), and have received concomitant total parenteral nutrition (7/69 [10.1%] vs 0 [0%]; P = 0.02) and/or steroids (22/69 [31.9%] vs 8/69 [11.6%]; P = 0.008). CART analysis identified age > 65 years, albumin < 3.2 g/dL, WBC count > 14.5 cells/mm3, and CrCl < 40 mL/min to be more common in hyperglycemic patients. In logistic regression, diabetes (odds ratio [OR] = 233; 95% CI, 19-2784) and excessive dose for renal function (OR = 42; 95% CI, 2-770) were identified as independent predictors for hyperglycemia in patients receiving gatifloxacin. After controlling for diabetes, concomitant steroids (OR = 5.7; 95% CI, 1.5-21.1) and excessive dose for renal function (OR = 4.9; 95% CI, 1.2-20.4) were associated with hyperglycemia in patients receiving gatifloxacin.

CONCLUSIONS

This retrospective, nested case-controlled study found that the risk of hyperglycemia increased in diabetic patients who received concomitant steroids or higher gatifloxacin doses than recommended by the manufacturer's prescribing information. The application of these data should be assessed for other fluoroquinolones used at higher doses.

A Review of Levofloxacin for the Treatment of Bacterial Infections

Completing its initial phases of drug development in the mid 1990s as the one of the first fluoroquinolones that could be used with confidence to treat respiratory tract infections, levofloxacin went on to become one of the most widely prescribed antibiotics in the world. Available in both oral (po) and intravenous (IV) formulations and with characteristics of over 90% bioavailability, distribution into both extracellular and intracellular pulmonary compartments, highly predictable pharmacokinetics with over 90% of the drug being excreted unchanged in urine, and reliable activity against a broad spectrum of clinically important pathogens, levofloxacin has been used successfully to treat patients with a variety of serious infectious diseases as well as common infections most often treated outside of the hospital setting. Results of clinical trials involving patients with respiratory tract, urinary tract, and skin infections have consistently shown rates of clinical success and bacteriological eradication that were comparable to other widely used broad-spectrum agents. Regimens of levofloxacin, initially involving total daily doses of 250 mg to 500 mg, but more recently regimens involving 750 mg doses, have been shown to be safe and effective. Nearly a decade and a half of clinical experience has defined a safety and tolerability profile that permits data-driven assessment of the risks and benefits of using levofloxacin. As resistance to currently available fluoroquinolones has emerged, the clinical value of levofloxacin deserves continued evaluation. However, consistently high rates of susceptibility of clinically important bacteria, especially among those bacteria that commonly cause respiratory tract infections, such as Streptococcus pneumoniae and Haemophilus influenzae, suggest that this agent will continue to be a widely used well past the 20-year anniversary of its introduction into the antibacterial armamentarium.

The insulinotropic effect of fluoroquinolones

Antimicrobial fluoroquinolones induce, with strongly varying frequency, life-threatening hypoglycemias, which is explained by their ability to block K(ATP) channels in pancreatic B-cells and thus to initiate insulin secretion. In apparent contradiction to this, we observed that none of the fluoroquinolones in this study (gatifloxacin, moxifloxacin, ciprofloxacin, and a number of fluorophenyl-substituted compounds) initiated insulin secretion of perifused mouse islets when the glucose concentration was basal (5mM). Only when the glucose concentration was stimulatory by itself (10mM), the fluoroquinolones enhanced secretion. The fluoroquinolones were ineffective on SUR1 Ko islets, which do not have functional K(ATP) channels. All of these fluoroquinolones depolarized the membrane potential of mouse B-cells (patch-clamping in the whole-cell mode). Using metabolically intact B-cells (perforated-patch mode) however, 100microM of gatifloxacin, ciprofloxacin or moxifloxacin were unable to depolarize when the glucose concentration was 5mM, whereas other K(ATP) channel blockers (tolbutamide and efaroxan) remained effective. Only at a very high concentration (500microM) gatifloxacin and moxifloxacin, but not ciprofloxacin induced repetitive depolarizations which could be antagonized by diazoxide. In the presence of 10mM glucose all fluoroquinolones which enhanced secretion markedly elevated cytosolic calcium concentration ([Ca(2+)](i)). In the presence of 5mM glucose gatifloxacin and moxifloxacin at 500microM but not at 100microM elevated [Ca(2+)](i). It is concluded that fluoroquinolones in the clinically relevant concentration range are not initiators, but rather enhancers of glucose-induced insulin secretion. The block of K(ATP) channels appears necessary but not sufficient to explain the hypoglycemic effect of fluoroquinolones.

Levofloxacin-associated hypoglycaemia complicated by pontine myelinolysis and quadriplegia

BACKGROUND

Central pontine myelinolysis (CPM) usually presents in chronic alcoholics and in patients in whom hyponatraemia has been corrected rapidly. However, CPM may occur in other clinical circumstances, including patients with severe hypoglycaemia. We describe the occurrence of CPM and quadriplegia in a patient who experienced fluoroquinolone-associated severe hypoglycaemia.

CASE REPORT

A 63-year-old man with Type 2 diabetes mellitus was admitted to hospital for resection of a large liposarcoma. Renal-dose levofloxacin was utilized as part of an antimicrobial regimen to treat post-operative peritonitis. On days 6-8 of levofloxacin therapy, the patient experienced recurrent hypoglycaemia despite total parenteral nutrition, 10% dextrose containing fluids and cessation of insulin therapy 3 days prior to the first hypoglycaemic episode. Hypoglycaemia resolved within 24 h of stopping levofloxacin. After a final and severe hypoglycaemic event, the patient developed quadriplegia and tonic left deviation of gaze. Magnetic resonance imaging revealed a high-intensity lesion in the central pons consistent with CPM.

CONCLUSIONS

Fluoroquinolones should be considered as a potential cause of hypoglycaemia. Severe hypoglycaemia has the potential to cause white matter lesions in the pons. Putative mechanisms include failure of membrane ion channels, oligodendrocyte apoptosis and oxidative stress of glucose reperfusion. Fluoroquinolone-associated hypoglycaemia and hypoglycaemia-induced quadriplegia are both rare and we believe this is the first case report linking the two events.

Prevalence of and risk factors for dysglycemia in patients receiving gatifloxacin and levofloxacin in an outpatient setting

STUDY OBJECTIVES

To assess the prevalence of dysglycemia (hypoglycemia or hyperglycemia) associated with oral levofloxacin and gatifloxacin therapy in an outpatient setting, and to determine the characteristics of patients who developed dysglycemia while receiving either fluoroquinolone.

DESIGN

Retrospective medical record review.

SETTING

Outpatient clinic of a Veterans Affairs teaching hospital.

PATIENTS

A total of 1573 patients who received oral levofloxacin (343 patients), gatifloxacin (589 patients), or azithromycin (as a control, 641 patients) between June 1, 2004, and May 31, 2006.

MEASUREMENTS AND MAIN RESULTS

Dysglycemia occurred in 33 patients: 13 (2.2%), 9 (2.6%), and 11 (1.7%), respectively, of those in the gatifloxacin, levofloxacin, and azithromycin groups. Of 13 patients who experienced a hyperglycemic event, 11 (84.6%) had diabetes mellitus. After adjustment for confounding factors, neither levofloxacin nor gatifloxacin were associated with increased odds of developing a dysglycemic event compared with azithromycin. Multivariate analysis demonstrated that lack of downward dosage adjustment based on creatinine clearance (odds ratio [OR] 10.3, 95% confidence interval [CI] 3.8-27.6), presence of diabetes (OR 17.1, 95% CI 3.1-94.9), or treatment with insulin (OR 5.3, 95% CI 1.8-15.7) or sulfonylureas (OR 3.6, 95% CI 1.3-10.4) independently increased dysglycemia risk. Obesity (body mass index > or = 30 kg/m(2)) was independently protective (OR 0.22, 95% CI 0.09-0.55) against dysglycemic events.

CONCLUSION

Levofloxacin and gatifloxacin were not significantly associated with increased dysglycemic events compared with azithromycin. Lack of downward fluoroquinolone dosage adjustment for renal function, presence of diabetes, and treatment with insulin or sulfonylureas each independently increased the risk of dysglycemia. Obesity was independently protective against dysglycemia. More data are needed on the contributing effects of diabetes, fluoroquinolone dosage, and concomitant drug therapy so that an appropriate risk-management strategy can be developed.

An evaluation of the effects of gatifloxacin on glucose homeostasis

INTRODUCTION

The United States labeling for gatifloxacin has been updated to include contradictions related to its reported association with dysglycemia. However, adequately controlled studies in acute care settings assessing the magnitude and clinical determinants of dysglycemia are lacking.

OBJECTIVES

To compare the hypoglycemic and hyperglycemic effects of gatifloxacin with ceftriaxone in hospitalized patients.

METHODS

A retrospective cohort study of hospitalized adult (> or =18 years) patients admitted with Community Acquired Pneumonia (CAP) or Acute Exacerbation of Chronic Bronchitis (AECB) in a US tertiary care hospital between 7/1/01 and 12/31/04 treated with gatifloxacin or ceftriaxone during hospital admission. Outcomes of interests were incidence of hypoglycemia (blood glucose levels <46 mg/dL) or hyperglycemia (>200 mg/dL) during up to 5 days of drug exposure. Risks for gatifloxacin and ceftriaxone were compared adjusting for variables previously reported to be independent predictors of hypoglycemia or hyperglycemia.

RESULTS

1504 patients met the study inclusion criteria. Compared to ceftriaxone, gatifloxacin was associated with an increased risk of hypoglycemia: (adjusted odds ratio (OR) 2.34, 95% confidence interval (CI) 1.4-4.0). The increased risk of hypoglycemia during exposure to gatifloxacin was similar in patients with and without a diagnosis of diabetes mellitus. Gatifloxacin was not associated with an increased risk for hyperglycemia (adjusted OR: 1.06 95% CI 0.8-1.4) considering the whole study cohort. However, stratification by diagnosis of diabetes, gatifloxacin treated patients appeared to have a reduced risk of hyperglycemia (adjusted OR: 0.4 95% CI 0.2-0.4) while non-diabetic gatifloxacin treated patients appeared to have an increased risk of hyperglycemia (adjusted OR: 1.64 95% CI 1.1-2.4).

CONCLUSION

The risk of dysglycemia with gatifloxacin in this population of hospitalized patients was not as high as previously reported in ambulatory patients. Although these results suggest gatifloxacin use is safer in acute care settings, we recommend that clinicians monitor blood glucose levels carefully or consider alternatives to gatifloxacin therapy whenever possible.

Efficient drug targeting to rat alveolar macrophages by pulmonary administration of ciprofloxacin incorporated into mannosylated liposomes for treatment of respiratory intracellular parasitic infections

The efficacy of pulmonary administration of ciprofloxacin (CPFX) incorporated into mannosylated liposomes (mannosylated CPFX-liposomes) for the treatment of respiratory intracellular parasitic infections was evaluated. In brief, mannosylated CPFX-liposomes with 4-aminophenyl-a-d-mannopyranoside (particle size: 1000 nm) were prepared, and the drug targeting to alveolar macrophages (AMs) following pulmonary administration was examined in rats. Furthermore, the antibacterial and mutant prevention effects of mannosylated CPFX-liposomes in AMs were evaluated by pharmacokinetic/pharmacodynamic (PK/PD) analysis. The targeting efficiency of CPFX to rat AMs following pulmonary administration of mannosylated CPFX-liposomes was significantly greater than that of CPFX incorporated into unmodified liposomes (unmodified CPFX-liposomes; particle size: 1000 nm). According to PK/PD analysis, the mannosylated CPFX-liposomes exhibited potent antibacterial effects against many bacteria although unmodified CPFX-liposomes were ineffective against several types of bacteria, and the probability of microbial mutation by mannosylated CPFX-liposomes was extremely low. The present study indicates that mannosylated CPFX-liposomes as pulmonary administration system could be useful for the treatment of respiratory intracellular parasitic infections.

Effects of gatifloxacin and levofloxacin on rates of hypoglycemia and hyperglycemia among elderly hospitalized patients

STUDY OBJECTIVES

To compare rates of hypoglycemia and hyperglycemia among elderly hospitalized patients with normal blood glucose concentrations at baseline who were receiving either gatifloxacin or levofloxacin, and to determine if appropriateness of their doses, according to their package inserts, was associated with hypoglycemia or hyperglycemia.

DESIGN

Retrospective cohort study.

SETTING

Integrated Veterans Administration (VA) health care system.

PATIENTS

Nine hundred thirty-seven elderly (>or= 65 yrs) patients with documented blood glucose levels of 65-140 mg/dl before receiving a fluoroquinolone.

MEASUREMENTS AND MAIN RESULTS

Between January 2003 and April 2004, 405 patients receiving levofloxacin met study criteria. In April 2004, gatifloxacin was substituted for levofloxacin on the formulary of this VA system. Thus, between April 2004 and December 2004, 532 patients received gatifloxacin. All blood glucose concentrations during hospitalization that were measured during fluoroquinolone therapy or within 72 hours of completion of therapy were reviewed. Demographic characteristics, comorbidities, insulin and oral hypoglycemic therapies, disease severity, blood glucose levels, and outcomes were recorded and compared between groups. The two groups were similar at baseline for all characteristics examined except previous hospitalization. In the logistic regression, gatifloxacin was independently associated with both hypoglycemia (adjusted odds ratio [AOR] 2.5, 95% confidence interval [CI] 1.2-5.7, p=0.04) and hyperglycemia (AOR 2.4, 95% CI 1.5-3.6, p<0.001). Improper dosage adjustment based on renal function was not associated with higher rates of hypoglycemia and hyperglycemia for either drug. Of the 532 patients receiving gatifloxacin, 465 (87.4%) received appropriate doses, yet gatifloxacin was associated with higher rates of hypoglycemia and hyperglycemia compared with patients receiving levofloxacin.

CONCLUSIONS

Higher rates of both hypoglycemia and hyperglycemia were noted among elderly hospitalized patients who received gatifloxacin compared with those receiving levofloxacin, irrespective of dosing.

Glycemic control and critical illness: is the kidney involved?

The pathophysiology, consequences, and management of hyperglycemia during critical illness is an important clinical issue. Uncontrolled hyperglycemia in this setting is associated with a variety of adverse events, including mortality. The kidneys have a major role in glucose and insulin metabolism, and emerging evidence suggests that they both are actively involved in the development, maintenance, and resolution of hyperglycemia. The development of acute kidney injury is also a risk in this setting. This article discusses potential approaches for efficient and effective management of hyperglycemia.