Fatal Hypoglycemia Associated with Levofloxacin

Hypoglycemia in non-diabetic in-patients at a teaching referral hospital in Iran

Purpose

This study aims to investigate comorbidities, clinical features, laboratory values, and diagnoses in non-diabetic patients experiencing hypoglycemic episodes.

Methods

A retrospective observational study was conducted at Shariati Hospital in Iran from 2016 to 2023. Seventy-four non-diabetic patients admitted with a diagnosis of hypoglycemia were included, while patients with diabetes were excluded. Demographic data, symptoms, and biochemical assessments were obtained from the hospital information system. Hypoglycemic episodes were identified based on low measured blood glucose, recorded medications for hypoglycemia treatment, or recorded codes indicating hypoglycemia. Hypoglycemia was defined as blood glucose below 70 mg/dL (3.9 mmol/L) along with two other criteria of the Whipple triad. Statistical analysis was performed using SPSS software (version 26).

Results

Among the enrolled patients, 63.5% were female, and 13.5% were elderly (≥ 65 years). The most common comorbidities observed were cardiovascular disease (20.3%), psychological disorders (20.3%), hypothyroidism (14.9%), and hypertension (8.1%). The prevalent symptoms included weakness, loss of consciousness, sweating, palpitations, dizziness, and tremors. Non-diabetic hypoglycemia was caused by factitious disorders, insulinoma, organ failure, and infection, respectively.

Conclusion

Due to the diverse range of clinical symptoms, hypoglycemia in non-diabetic patients may be diagnosed late, leading to misdiagnoses such as psychological disorders or seizures. It is crucial to consider the possibility of hypoglycemia in non-diabetic patients and determine its underlying cause. Given the poor prognosis associated with hypoglycemia, timely interventions are essential.

Hypoglycemia and anxiolysis mediated by levofloxacin treatment in diabetic rats

Purpose

The present study was designed to determine the effect of levofloxacin (LVX) treatment on the blood glucose level, insulin sensitivity, anxiety level, nitrite and MDA level of STZ induced diabetic rats.

Methods

Wistar rats were used in the present study. The rats were made diabetic by the administration of single dose of STZ (45 mg/kg, i.p.) and NAD (50 mg/kg, i.p.). The rats with the blood glucose level greater than 200 mg/dl were considered as diabetic (confirmed at day-3 of STZ-NAD administration). The non-diabetic rats were considered as control and received saline.Diabetic rats received metformin (50 mg/kg, p.o.) and LVX (20, 25, 30 and 35 mg/kg, i.p.) daily for 14 days (starting from the day at which STZ was injected). Following administration on 14th day,the blood sample was collected and the rats were subjected to behavioral assays for the determination of locomotor activity and anxiety level. Plasma was separated and used for the estimation ofnitrite and malondialdehyde (MDA)level. On 15th day OGTT was performed in the overnight fasted rats for the assessment of insulin sensitivity.

Results

The results obtained suggested that the administration of STZ-NAD induced the hyperglycemia at day-3 of administration. Diabetic rats displayed the significant increase in blood glucose, anxiety related behavior, MDA level while significant decrease in the insulin sensitivity and plasma nitrite level. Daily administration of metformin to the diabetic rats decreased the blood glucose level, increased the time spent at the center of open field, reversed the anxiety related behavior in LDT and EPM, did not affect the plasma nitrite level, decreased the plasma MDA level, decreased the fasting glucose level and AUC in OGTT assay. LVX (30 and 35 mg/kg) treatment significantly decreased the blood glucose level of diabetic rats. LVX (20, 25 and 30 mg/kg) treatment significantly decreased the number of square crossing while LVX (20, 25, 30 and 35) treatment significantly increased the time spent at the center of the field by the diabetic rats. LVX (20 and 35 mg/kg) treatment significantly reversed the STZ induced anxiety in LDT while LVX (20, 30 and 35 mg/kg) treatment significantly reversed the STZ induced anxiety in EPM test. LVX (20, 25 and 35 mg/kg) treatment significantly increased the plasma nitrite level and LVX (20-35 mg/kg) treatment significantly decreased the MDA level of diabetic rats. Further only LVX (35 mg/kg) treatment significantly decreased the fasting glucose level and increased the AUC of diabetic rats.

Conclusion

In conclusion, STZ-NAD administration increased the blood glucose level, anxiety related behavior, decreased the plasma nitrite and increased the MDA level. LVX administration potentiated the diabetogenic effects of STZ-NAD in rats. Daily administration of LVX decreased the blood glucose level of diabetic rats. LVX administration alleviated the STZ induced anxiety in OFT, LDT and EPM test. LVX administration increased the plasma nitrite level and decreased the lipid peroxidation in diabetic rats.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01234-0.

Skeletal muscle relaxant drug-drug-drug interactions and unintentional traumatic injury: Screening to detect three-way drug interaction signals

AIM

The aim of this study was to identify skeletal muscle relaxant (SMR) drug-drug-drug interaction (3DI) signals associated with increased rates of unintentional traumatic injury.

METHODS

We conducted automated high-throughput pharmacoepidemiologic screening of 2000-2019 healthcare data for members of United States commercial and Medicare Advantage health plans. We performed a self-controlled case series study for each drug triad consisting of an SMR base-pair (i.e., concomitant use of an SMR with another medication), and a co-dispensed medication (i.e., candidate interacting precipitant) taken during ongoing use of the base-pair. We included patients aged ≥16 years with an injury occurring during base-pair-exposed observation time. We used conditional Poisson regression to calculate adjusted rate ratios (RRs) with 95% confidence intervals (CIs) for injury with each SMR base-pair + candidate interacting precipitant (i.e., triad) versus the SMR-containing base-pair alone.

RESULTS

Among 58 478 triads, 29 were significantly positively associated with injury; confounder-adjusted RRs ranged from 1.39 (95% CI = 1.01-1.91) for tizanidine + omeprazole with gabapentin to 2.23 (95% CI = 1.02-4.87) for tizanidine + diclofenac with alprazolam. Most identified 3DI signals are new and have not been formally investigated.

CONCLUSION

We identified 29 SMR 3DI signals associated with increased rates of injury. Future aetiologic studies should confirm or refute these SMR 3DI signals.

Fatal hypoglycemia with ciprofloxacin in a dialysis patient: A case report

In patients with renal dysfunction, it is important to avoid prescribing fluoroquinolones including ciprofloxacin.

Non- pancreatic neuroendocrine tumour presenting with hypoglycemia in an elderly patient

Background

Hypoglycemia is a common, symptom seen in individuals. Hypoglycemia in the elderly is both under-recognized and misdiagnosed due to nonspesific hypoglycemic symptoms and accompanying comorbidities in this population. In diabetic individuals, hypoglycemia is most commonly caused by administering insulin or sulphonylureas and insulin secretagogues. Other drugs, such as antibiotics or beta-blockers, have been reported to reduce blood glucose to abnormally low levels. Hypoglycemia in non-diabetic patients is considered a rare event, and the possible reasons may be reactive hypoglycemia, insulin-secreting tumours and other malignancies, hypopituitarism, hypocortisolism, alcohol abuse, inappropriate insulin self-administration, malnutrition, renal failure and sepsis.

Case

An 86- year- old male was admitted to the emergency department with hypoglycemia diagnosed with non-pancreatic neuroendocrine tumour (NET) on lung secreting insulin. No surgical intervention or chemotherapy was planned due to patients age and comorbidities so best supportive care was planned. We used prednisone for symptomatic treatment of hypoglycemia and the patient has been followed up periodically. In this period he had no hypoglycemic attack.

Conclusion

For patients with hypoglycemia who are unable/decline to receive any further treatment, low dose glucocorticoid is a good choice to achieve normoglycemia. It seems to be more cost effective compared to other treatment options. Furthermore hospitalisation rates may decrease due to decreased hypogylcemic attacks.

Risk of hospitalization from drug-drug interactions in the Elderly: real-world evidence in a large administrative database

The aim of this study was to assess the risk of hospitalization associated with the concomitant prescription of 10 highly prevalent drug-drug interactions (DDIs) among all individuals aged ≥65 residing in Bologna's area, Italy. We used incidence density sampling, and the effect of current (last month) and past (≥30 days before) exposure to DDI was investigated through conditional multivariable logistic regression analysis. Two DDIs were associated with increased hospitalization due to DDI related conditions: ACE-inhibitors/ diuretics plus glucocorticoids (current DDI: OR 2.36, 95% CI 1.94-2.87; past DDI: OR 1.36, 95% CI 1.12-1.65) and antidiabetic therapy plus current use of fluoroquinolones (OR 4.43, 95% CI 1.61-11.2). Non-Steroidal Anti-inflammatory Drugs (NSAIDs) increased the risk of re-bleeding in patients taking Selective Serotonin Reuptake Inhibitors (OR 5.56, 95% CI 1.24-24.9), while no significant effect was found in those without a history of bleeding episodes. Concomitant prescription of NSAIDs and ACE-inhibitors/diuretics in patients with a history of high-risk conditions was infrequent. Within the pattern of drug prescriptions in the older population of Bologna's area, we distinguished DDIs with actual clinical consequences from others that might be considered generally safe. Observed prescribing habits of clinicians reflect awareness of potential interactions in patients at risk.

Ciprofloxacin and risk of hypolycemia in non-diabetic patients

Background

Fluoroquinolones have been associated with hypoglycemia in patients taking diabetic medications, most commonly due to drug-drug interactions and other associated risk factors. Except for four published case reports, there are no studies that have found positive associations between ciprofloxacin and hypoglycemia. In all but one of the cases, ciprofloxacin was taken with other hypoglycemic drugs. Recently, the Eritrean National Pharmacovigilance Centre received a serious case of hypoglycemia with recurrent episodes in a young and healthy patient without diabetes following use of oral ciprofloxacin. The aim of the present study is therefore to assess the causal relationship between ciprofloxacin and hypoglycemia in patients without diabetes using the World Health Organization-Uppsala Monitoring Centre global adverse drug reaction database (VigiBase®).

Methods

A search was made on the World Health Organization global adverse drug reaction database (August 15, 2018) using “ciprofloxacin” as the drug substance and “hypoglycemia” as the reaction term. Cases that used hypoglycemic drugs (patients with diabetes) concurrently with ciprofloxacin and those with a completeness score below 50% were excluded to control for confounders and to improve the strength of the data. Hill criteria were used to assess causation.

Results

A total of 35 cases of hypoglycemia reported since 1989 from 17 countries in patients without diabetes associated with ciprofloxacin use with a median time to onset of 4 days were retrieved. The cases have a median age of 64 years (interquartile range, 50–85) with a similar male–to-female ratio. Ciprofloxacin was the only suspect and the sole drug administered in 48.5% of the cases. In ten cases, hypoglycemia abated following withdrawal of ciprofloxacin, and reaction recurred in one case on the subsequent rechallenge. Hypoglycemia was marked as “serious” in 20 cases, and the outcome was fatal in two cases.

Conclusions

This assessment found a suggestive causal link between use of ciprofloxacin and hypoglycemia in patients without diabetes.

Successful Use of Octreotide Therapy for Refractory Levofloxacin-Induced Hypoglycemia: A Case Report and Literature Review

Fluoroquinolones are commonly prescribed antimicrobials that have been implicated in alterations of glucose metabolism. We report a case of refractory fluoroquinolone-induced hypoglycemia in a patient with type-2 diabetes mellitus on glipizide that was successfully treated with octreotide. A patient was admitted with hypoglycemia after having been initiated on levofloxacin therapy. Despite treating the hypoglycemia supportively with multiple boluses of 25 g of dextrose, a continuous dextrose infusion, and glucagon, the patient experienced repeated episodes of rebound hypoglycemia. The persistent hypoglycemia was eventually reversed with the administration of subcutaneous octreotide. Clinicians should be cognizant of this adverse effect of fluoroquinolones, as well as predisposing risk factors, and consider octreotide as an adjunctive therapy for refractory hypoglycemia cases.

[Research on Insufficient Information for Pharmaceutical Products]

 Several issues concerning medicines remain unclear, including the availability of known, but not easily recognizable information. This review evaluates the mechanisms of side effects and the various risk indications included in package inserts. The results can be summarized as follows. 1) Short-term exposure to gatifloxacin significantly induced insulin secretion and increased the cytosolic Ca²⁺ concentration of islet cells by augmenting extracellular Ca²⁺ influx and its release from the endoplasmic reticulum. Alternatively, there was a decline in the cellular insulin level and reactivity to sulfonylurea after prolonged exposure. The insulin depletion was greater than that produced by other fluoroquinolones. 2) The elution of di(2-ethylhexyl)phthalate (DEHP) from the infusion set could be associated with the solubilizers in the injection medicines. The package inserts of several products containing polysorbate or ethanol had no warning about DEHP. Although there was a slight correlation between polysorbate content and descriptions on package inserts, the use of DEHP-containing devices was prohibited for some products, even with limited amounts of polysorbate. Therefore, the package insert statements should be reviewed to reflect appropriately the extent of DEHP elution. 3) Risk management plan consists of strategies to minimize the potential risks of medicines. One approach could be to introduce reminders on package inserts; however, of 268 potential risks associated with 81 products, 56 were not mentioned in package inserts. Because most postmarketing pharmacovigilance plans depend on spontaneous reporting by healthcare personnel, the descriptions on package inserts should be reexamined.

Patients With Long-QT Syndrome Caused by Impaired hERG-Encoded Kv11.1 Potassium Channel Have Exaggerated Endocrine Pancreatic and Incretin Function Associated With Reactive Hypoglycemia

Supplemental Digital Content is available in the text.

Background:

Loss-of-function mutations in hERG (encoding the K_v11.1 voltage-gated potassium channel) cause long-QT syndrome type 2 (LQT2) because of prolonged cardiac repolarization. However, K_v11.1 is also present in pancreatic α and β cells and intestinal L and K cells, secreting glucagon, insulin, and the incretins glucagon-like peptide-1 (GLP-1) and GIP (glucose-dependent insulinotropic polypeptide), respectively. These hormones are crucial for glucose regulation, and long-QT syndrome may cause disturbed glucose regulation. We measured secretion of these hormones and cardiac repolarization in response to glucose ingestion in LQT2 patients with functional mutations in hERG and matched healthy participants, testing the hypothesis that LQT2 patients have increased incretin and β-cell function and decreased α-cell function, and thus lower glucose levels.

Methods:

Eleven patients with LQT2 and 22 sex-, age-, and body mass index–matched control participants underwent a 6-hour 75-g oral glucose tolerance test with ECG recording and blood sampling for measurements of glucose, insulin, C-peptide, glucagon, GLP-1, and GIP.

Results:

In comparison with matched control participants, LQT2 patients had 56% to 78% increased serum insulin, serum C-peptide, plasma GLP-1, and plasma GIP responses (P=0.03–0.001) and decreased plasma glucose levels after glucose ingestion (P=0.02) with more symptoms of hypoglycemia (P=0.04). Sixty-three percent of LQT2 patients developed hypoglycemic plasma glucose levels (<70 mg/dL) versus 36% control participants (P=0.16), and 18% patients developed serious hypoglycemia (<50 mg/dL) versus none of the controls. LQT2 patients had defective glucagon responses to low glucose, P=0.008. β-Cell function (Insulin Secretion Sensitivity Index-2) was 2-fold higher in LQT2 patients than in controls (4398 [95% confidence interval, 2259–8562] versus 2156 [1961–3201], P=0.03). Pharmacological K_v11.1 blockade (dofetilide) in rats had similar effect, and small interfering RNA inhibition of hERG in β and L cells increased insulin and GLP-1 secretion up to 50%. Glucose ingestion caused cardiac repolarization disturbances with increased QTc intervals in both patients and controls, but with a 122% greater increase in QTcF interval in LQT2 patients (P=0.004).

Conclusions:

Besides a prolonged cardiac repolarization phase, LQT2 patients display increased GLP-1, GIP, and insulin secretion and defective glucagon secretion, causing decreased plasma glucose and thus increased risk of hypoglycemia. Furthermore, glucose ingestion increased QT interval and aggravated the cardiac repolarization disturbances in LQT2 patients.

Clinical Trial Registration:

URL: http://clinicaltrials.gov. Unique identifier: NCT02775513.

A Review of New Fluoroquinolones : Focus on their Use in Respiratory Tract Infections

The new respiratory fluoroquinolones (gatifloxacin, gemifloxacin, levofloxacin, moxifloxacin, and on the horizon, garenoxacin) offer many improved qualities over older agents such as ciprofloxacin. These include retaining excellent activity against Gram-negative bacilli, with improved Gram-positive activity (including Streptococcus pneumoniae and Staphylococcus aureus). In addition, gatifloxacin, moxifloxacin and garenoxacin all demonstrate increased anaerobic activity (including activity against Bacteroides fragilis). The new fluoroquinolones possess greater bioavailability and longer serum half-lives compared with ciprofloxacin. The new fluoroquinolones allow for once-daily administration, which may improve patient adherence. The high bioavailability allows for rapid step down from intravenous administration to oral therapy, minimizing unnecessary hospitalization, which may decrease costs and improve quality of life of patients. Clinical trials involving the treatment of community-acquired respiratory infections (acute exacerbations of chronic bronchitis, acute sinusitis, and community-acquired pneumonia) demonstrate high bacterial eradication rates and clinical cure rates. In the treatment of community-acquired respiratory tract infections, the various new fluoroquinolones appear to be comparable to each other, but may be more effective than macrolide or cephalosporin-based regimens. However, additional data are required before it can be emphatically stated that the new fluoroquinolones as a class are responsible for better outcomes than comparators in community-acquired respiratory infections. Gemifloxacin (except for higher rates of hypersensitivity), levofloxacin, and moxifloxacin have relatively mild adverse effects that are more or less comparable to ciprofloxacin. In our opinion, gatifloxacin should not be used, due to glucose alterations which may be serious. Although all new fluoroquinolones react with metal ion-containing drugs (antacids), other drug interactions are relatively mild compared with ciprofloxacin. The new fluoroquinolones gatifloxacin, gemifloxacin, levofloxacin, and moxifloxacin have much to offer in terms of bacterial eradication, including activity against resistant respiratory pathogens such as penicillin-resistant, macrolide-resistant, and multidrug-resistant S. pneumoniae. However, ciprofloxacin-resistant organisms, including ciprofloxacin-resistant S. pneumoniae, are becoming more prevalent, thus prudent use must be exercised when prescribing these valuable agents.

HERG Protein Plays a Role in Moxifloxacin-Induced Hypoglycemia

The purpose of this study was to investigate the effect of moxifloxacin on HERG channel protein and glucose metabolism. HERG expression was investigated using immunohistochemistry. The whole-cell patch clamp method was used to examine the effect of moxifloxacin on HERG channel currents. A glucose tolerance test was used to analyze the effects of moxifloxacin on blood glucose and insulin concentrations in mice. Results show that HERG protein was expressed in human pancreatic β-cells. Moxifloxacin inhibited HERG time-dependent and tail currents in HEK293 cells in a concentration-dependent manner. The IC50 of moxifloxacin inhibition was 36.65 μmol/L. Moxifloxacin (200 mg/kg) reduced blood glucose levels and increased insulin secretion in wild-type mice at 60 min after the start of the glucose tolerance test. In contrast, moxifloxacin did not significantly alter blood glucose and insulin levels in HERG knockout mice. Serum glucose levels increased and insulin concentrations decreased in HERG knockout mice when compared to wild-type mice. The moxifloxacin-induced decrease in blood glucose and increase in insulin secretion occurred via the HERG protein; thus, HERG protein plays a role in insulin secretion.

Safety and tolerability profile of second-line anti-tuberculosis medications

Tuberculosis (TB) remains a major public health problem, representing the second leading cause of death from infectious diseases globally, despite being nearly 100 % curable. Multidrug-resistant (MDR)-TB, a form of TB resistant to isoniazid and rifampicin (rifampin), two of the key first-line TB drugs, is becoming increasingly common. MDR-TB is treated with a combination of drugs that are less effective but more toxic than isoniazid and rifampicin. These drugs include fluoroquinolones, aminoglycosides, ethionamide, cycloserine, aminosalicyclic acid, linezolid and clofazimine among others. Minor adverse effects are quite common and they can be easily managed with symptomatic treatment. However, some adverse effects can be life-threatening, e.g. nephrotoxicity due to aminoglycosides, cardiotoxicity due to fluoroquinolones, gastrointestinal toxicity due to ethionamide or para-aminosalicylic acid, central nervous system toxicity due to cycloserine, etc. Baseline evaluation may help to identify patients who are at increased risk for adverse effects. Regular clinical and laboratory evaluation during treatment is very important to prevent adverse effects from becoming serious. Timely and intensive monitoring for, and management of adverse effects caused by, second-line drugs are essential components of drug-resistant TB control programmes; poor management of adverse effects increases the risk of non-adherence or irregular adherence to treatment, and may result in death or permanent morbidity. Treating physicians should have a thorough knowledge of the adverse effects associated with the use of second-line anti-TB drugs, and routinely monitor the occurrence of adverse drug reactions. In this review, we have compiled safety and tolerability information regarding second-line anti-TB drugs in both adults and children.

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.

Discovery of FDA-approved drugs as inhibitors of fatty acid binding protein 4 using molecular docking screening

We first identified fluorescein, ketazolam, antrafenine, darifenacin, fosaprepitant, paliperidone, risperidone, pimozide, trovafloxacin, and levofloxacin as inhibitors of fatty acid binding protein 4 using molecular docking screening from FDA-approved drugs. Subsequently, the biochemical characterizations showed that levofloxacin directly inhibited FABP4 activity in both the in vitro ligand displacement assay and cell-based function assay. Furthermore, levofloxacin did not induce adipogenesis in adipocytes, which is the major adverse effect of FABP4 inhibitors.

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.

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.

The metabolic advantage of tumor cells

1- Oncogenes express proteins of "Tyrosine kinase receptor pathways", a receptor family including insulin or IGF-Growth Hormone receptors. Other oncogenes alter the PP2A phosphatase brake over these kinases. 2- Experiments on pancreatectomized animals; treated with pure insulin or total pancreatic extracts, showed that choline in the extract, preserved them from hepatomas. Since choline is a methyle donor, and since methylation regulates PP2A, the choline protection may result from PP2A methylation, which then attenuates kinases. 3- Moreover, kinases activated by the boosted signaling pathway inactivate pyruvate kinase and pyruvate dehydrogenase. In addition, demethylated PP2A would no longer dephosphorylate these enzymes. A "bottleneck" between glycolysis and the oxidative-citrate cycle interrupts the glycolytic pyruvate supply now provided via proteolysis and alanine transamination. This pyruvate forms lactate (Warburg effect) and NAD+ for glycolysis. Lipolysis and fatty acids provide acetyl CoA; the citrate condensation increases, unusual oxaloacetate sources are available. ATP citrate lyase follows, supporting aberrant transaminations with glutaminolysis and tumor lipogenesis. Truncated urea cycles, increased polyamine synthesis, consume the methyl donor SAM favoring carcinogenesis. 4- The decrease of butyrate, a histone deacetylase inhibitor, elicits epigenic changes (PETEN, P53, IGFBP decrease; hexokinase, fetal-genes-M2, increase). 5- IGFBP stops binding the IGF - IGFR complex, it is perhaps no longer inherited by a single mitotic daughter cell; leading to two daughter cells with a mitotic capability. 6- An excess of IGF induces a decrease of the major histocompatibility complex MHC1, Natural killer lymphocytes should eliminate such cells that start the tumor, unless the fever prostaglandin PGE2 or inflammation, inhibit them...

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.

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.

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.

Practical strategies to normalize hyperglycemia without undue hypoglycemia in type 2 diabetes mellitus

Hypoglycemia is a common problem in pharmacologically treated patients with type 2 diabetes mellitus and can be a major barrier to achieving optimal glycemic control. For practitioners to minimize and treat hypoglycemia, it is important to understand the physiology, risk factors, and medications associated with hypoglycemia. Through education, lifestyle modifications, medication adjustments, and possibly re-examining glycemic goals, practitioners can reduce the incidence of hypoglycemia while still decreasing the risk of microvascular complications associated with hyperglycemia.

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.

Fatal hypoglycemia with levofloxacin use in an elderly patient in the post-operative period

BACKGROUND AND AIM

Fluoroquinolones are antimicrobial agents with a broad spectrum of activity against gram-positive, gram-negative, and anaerobic organisms. They are widely used in surgical practice and are generally considered safe. Hypoglycemia because of use of levofloxacin is a rarely reported complication. This report of a case of a surgical patient highlights this potentially fatal complication.

PATIENT

An elderly, non-diabetic patient with renal impairment presented with a possible duodenal perforation. After successful surgery, the patient developed recurrent hypoglycemic episodes in the post-operative period after use of levofloxacin. Delay in recognition of the cause of hypoglycemia led to irreversible brain damage and death.

RESULTS

The calculated Naranjo adverse drug reaction probability scale criteria suggest the possibility that these episodes were related to levofloxacin. The mechanism of hypoglycemia with levofloxacin relates to the potential inhibition of the K(ATP) channel on the pancreatic beta cell by the drug.

CONCLUSION

The case report highlights the need to be aware of this potentially fatal complication of a drug commonly used in surgical practice.

The safety profile of moxifloxacin and other fluoroquinolones in special patient populations

BACKGROUND

Fluoroquinolones, including ciprofloxacin, levofloxacin, gemifloxacin, and moxifloxacin, represent a major advance in the development of antimicrobial agents. They offer significant activity against Gram-negative pathogens, while more advanced generation fluoroquinolones including levofloxacin, gemifloxacin, and moxifloxacin are significantly active against Gram-positive (e.g., Streptococcus pneumoniae for some members of the class), typical, atypical, and anaerobic pathogens. Fluoroquinolones have a pharmacokinetic/pharmacodynamic profile that exhibits concentration-dependent killing and good oral absorption, allowing for once-daily dosing.

OBJECTIVE

Review of data from fluoroquinolone studies, with an emphasis on the associated rare, but potentially clinically important, adverse events in specific patient populations. Review of clinical efficacy is included where relevant to the topic under discussion.

METHODS

A literature search was conducted using terms including fluoroquinolones, moxifloxacin, ciprofloxacin, levofloxacin, gatifloxacin, gemifloxacin, safety, adverse events, drug interactions, and pharmacokinetic parameters to identify literature providing information regarding the safety profile of specified fluoroquinolones in special patient populations (i.e., the elderly, patients with liver disease, kidney disease, glycemic disorder, those at risk for cardiovascular events). Although specific date criteria were not applied to the search, preference was given to more recent publications. Online databases searched include MEDLINE and EMBASE and relevant textbooks were utilized as well.

FINDINGS

Fluoroquinolones, when used either as monotherapy or as combination therapy depending on their individual indications, attain adequate concentrations for treating infections in different target sites, including epithelial lining fluid, alveolar macrophages, skin, and gastrointestinal tissues. Overall, fluoroquinolones have predictable and mild-to-moderate adverse-event profiles and are generally well tolerated. Findings of this review are limited by the availability of publications and case reports.

CONCLUSIONS

Fluoroquinolones, are associated with rare, but clinically important, adverse events in special patient populations (including the elderly; those with hepatic, renal, or glycemic disorders; and those at risk for cardiovascular events). Recognition of differences in the clinical efficacy and safety profiles of fluoroquinolones in special patient populations should lead to better antimicrobial agent selection.

Management of diabetes-related hypoglycemia

Iatrogenic hypoglycemia is the main factor limiting aggressive and optimal diabetes management. Rather than being an inevitable consequence of optimal glycemic control, however, hypoglycemia is avoidable and generally straightforward to manage when it occurs. Professional caregivers, patients, and their families are often fearful of hypoglycemia, even though most episodes are minor and easily self-treated. Understanding the factors contributing to hypoglycemia risk and how to minimize its occurrence is an essential part of diabetes care. Building on the physiologic fundamentals presented in the accompanying review, the incidence, mortality/morbidity, clinical symptoms, severity classification, and psychosocial impact of hypoglycemia are described here. Appropriate selection and titration of therapeutic agents, including insulin analogs with more predictable time-action profiles than human insulin formulations, can reduce hypoglycemia risk. Patient education about hypoglycemia prevention, including symptom recognition and necessity of rapid treatment, behavioral modification, and the importance of frequent blood glucose monitoring should accompany all therapeutic interventions.

Gatifloxacin-induced dysglycemia

PURPOSE

The development of gatifloxacin-induced dysglycemia in 13 patients is described; the details of the 3 most severe cases are presented.

SUMMARY

Three elderly patients developed dysglycemia after initiation of gatifloxacin therapy. Both patients who developed hypoglycemia were receiving concomitant insulin or oral antidiabetic agents. Repeated doses of dextrose were required for management. The Naranjo et al. probability rating scale revealed that gatifloxacin was the probable cause in the majority of the 13 cases, primarily because of the temporal relationship with gatifloxacin and, in some instances, resolution of dysglycemia after drug discontinuation. Although the mechanism of gatifloxacin-induced hyperglycemia is not known, in vitro studies have found that certain quinolone antimicrobials can lower serum glucose levels by blocking adenosine 5'-triphosphate-dependent potassium channels in the pancreatic beta-cell, stimulating insulin release. It is difficult to unequivocally implicate gatifloxacin as the only cause of dysglycemia in the cases presented, as there are many explanations for poor glycemic control in hospitalized patients, such as stress, infection, decreased renal function, and concomitant drug therapies. However, the patients' medication regimens appeared to be stable before gatifloxacin administration.

CONCLUSION

Thirteen patients developed dysglycemia after receiving gatifloxacin. Gatifloxacin was found to be the probable cause in the majority of cases.

Gatifloxacin Induces Augmented Insulin Release and Intracellular Insulin Depletion of Pancreatic Islet Cells

Many hypoglycemic and hyperglycemic episodes associated with clinical use of gatifloxacin (GFLX), a novel fluoroquinolone antimicrobial agent, have been reported in recent years. Some have reported hypoglycemia induced by fluoroquinolones, indicating that these agents may stimulate insulin secretion from pancreatic islet cells. In this study, we investigated the effect of GFLX on insulin homeostasis in islet cells using the insulin secreting cell line, HIT-T15. After 1 h incubation with over 100 microM of GFLX, insulin secretion from the cells was significantly augmented. However, the augmentation of insulin release induced by GFLX subsequently reached a plateau. Coincidentally, cellular insulin was decreased by 120 h incubation, and reactivity to re-stimulation by sulfonylurea was suppressed. The GFLX insulin depletion effect was stronger than the effects produced by such other fluoroquinolones as levofloxacin and ciprofloxacin. This study suggests that GFLX should induce insulin oversecretion from pancreatic islet cells in the short-term, and decrease insulin productivity or increase insulin disintegration in the long-term. These results are consistent with the clinical results of GFLX finding that hypoglycemic episodes were seen after a first single administration, and most hyperglycemic episodes were seen more than 2 d after the start of administration.

Effect of levofloxacin on serum glucose concentration in rats

To clarify the mechanism of fluoroquinolone-induced abnormalities in blood glucose, the effect of levofloxacin on serum glucose concentration was investigated in rats. Rats received an intravenous injection of levofloxacin and their arterial blood was sampled periodically. The serum glucose concentration decreased after an injection of 100 mg/kg of levofloxacin, while it increased at levofloxacin 300 mg/kg. The serum immunoreactive insulin concentration increased as the dose of levofloxacin increased. The serum epinephrine concentration was rapidly elevated by levofloxacin at 300 mg/kg. The serum histamine concentration increased after injections of levofloxacin, 200 and 300 mg/kg. Diphenhydramine (1 mg/kg) antagonized the hyperglycemia induced by 300 mg/kg of levofloxacin. In an in vitro study, the release of epinephrine from the adrenal medulla in the presence of levofloxacin was determined. Levofloxacin (300 microg/ml) did not affect epinephrine release from the adrenal medulla. Levofloxacin can induce hypoglycemia and hyperglycemia in rats. Levofloxacin can promote histamine release, leading to an increased serum epinephrine concentration and hyperglycemia.

Incidence and prognostic significance of hypoglycemia in hospitalized non-diabetic elderly patients

BACKGROUND AND AIMS

To assess the incidence and prognostic value of hypoglycemia in hospitalized non-diabetic elderly patients.

METHODS

An observational retrospective study, with a 3-year follow-up, was performed in a series of 678 patients aged over 65 years, admitted between January 1 2001 and December 31 2001 to the Units of Gerontology and Geriatrics of the Careggi University Hospital, Florence, Italy. Patients with diabetes mellitus were excluded. To determine the cumulative incidence of hypoglycemia, all measurements of venous or capillary blood glucose during hospital stay were taken into account. In-hospital mortality was determined from hospital discharge records. Information on all-cause, three-year mortality after hospital admission was obtained from the City of Florence Registry Office.

RESULTS

Hypoglycemia was observed in 8.6% of patients, and was asymptomatic in about 25% of cases. In-hospital mortality was significantly higher in patients with hypoglycemia (41.4% vs 14.3%; p<0.001), even after adjustment for potential confounders, including comorbidity, indices of malnutrition, and pharmacological treatment (adjusted OR 2.17[1.25;3.85]). 3-year mortality was significantly higher in patients with hypoglycemia during hospital stay, but the difference was not significant after adjustment for confounders.

CONCLUSIONS

Hypoglycemia is a prognostic marker of in-hospital mortality in non-diabetic hospitalized patients, even after adjustment for comorbidity and indices of malnutrition. Instead, it does not seem to have any relevant independent prognostic value in the longer term.

[Clinically significant toxicity and tolerance of the main antibiotics used in lower respiratory tract infections]

The purpose of this article was not to review all reported adverse reactions of antibiotics used in the treatment of lower respiratory tract infections but rather to focus either on those which might have an impact on observance, efficacy, and resistance, or on rare but life-threatening adverse effects such as torsade de pointe. The latter are mostly predictable and prescribers should adhere to precautions and contraindications. For new antibiotics, the number of patients enrolled in phase I to III clinical trials is far to small to detect such rare adverse effects and large post registration tolerance surveys are mandatory. ss-lactams are well tolerated. The risk of anaphylactic reaction is magnified by patient reports and can be reduced by skin testing. Macrolides are well tolerated as well. The risk of cardiac toxicity should be reduced by assessing individual susceptibility and avoiding drug interactions. The tolerance to telithromycin, a new ketolide, is similar to that of macrolides. Serious toxic reactions such as convulsions, tendon rupture, torsade de pointe, and hypoglycemia are associated with the use of fluoroquinolones. Most of these adverse reactions can be often circumvented by avoiding exposure patients at risk. Quinupristin/dalfopristin can induce arthralgia and myalgia and the major adverse effects of linezolid are IMAO like reactions, reversible myelosuppression, and peripheral neuropathy. Most of the adverse antibiotic reactions are reported when precautions of use in susceptible patients are not taken into account. When they are, the safety/risk ratio is good.

Levofloxacin-Induced Hypoglycemia in a Nondiabetic Patient

The fluoroquinolones can cause severe hypoglycemia in older individuals with diabetes who are taking oral hypoglycemic agents. We describe a patient without diabetes who had new-onset hypoglycemia when given oral levaquin for pneumonia that developed after cardiac bypass surgery. The condition manifested with profound neurologic disturbances and required intravenous dextrose and parenteral glucagon for treatment. No other cause could be identified, and the problem remitted a few days after administration of the antibiotic was stopped. Laboratory evaluation showed relatively inappropriate insulin elevation at the time of the hypoglycemic episodes, consistent with pancreatic beta-cell stimulation. The report highlights glucose-lowering as an adverse effect of the fluoroquinolone class of antibiotics in persons without diabetes or taking hypoglycemic medication. Although levaquin is useful as broad-spectrum therapy in a variety of situations, clinicians should be cognizant of the occurrence of potentially serious or even fatal hypoglycemia with its use.

Hypoglycemia-induced anoxic brain injury possibly associated with levofloxacin

Reports linking alterations in blood glucose concentrations with fluoroquinolones, mostly gatifloxacin and ciprofloxacin, have been published. We describe an elderly, non-diabetic patient with steroid-induced hyperglycemia prescribed glyburide who later developed severe hypoglycemia resulting in anoxic brain injury soon after initiating therapy with levofloxacin.

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

STUDY OBJECTIVES

To compare rates of blood glucose abnormalities in hospitalized patients receiving fluoroquinolones or ceftriaxone, and to describe the characteristics of patients who develop blood glucose abnormalities while receiving these agents.

DESIGN

Retrospective chart review.

SETTING

Two community-based hospitals in the Houston, Texas, region.

PATIENTS

Seventeen thousand one hundred eight patients who received fluoroquinolones or ceftriaxone; of those, 101 received levofloxacin, gatifloxacin, or ceftriaxone and also had serum glucose concentrations above 200 or below 50 mg/dl within 72 hours of receiving the drug.

MEASUREMENTS AND MAIN RESULTS

Baseline demographics of patients with glucose abnormalities while receiving gatifloxacin, levofloxacin, or ceftriaxone were similar. Mean +/- SD patient age, weight, and estimated creatinine clearance were 67 +/- 17 years, 79 +/- 21 kg, and 52 +/- 32 ml/minute, respectively. Dysglycemia rates relative to treatment were as follows: gatifloxacin 76 (1.01%) of 7540 patients, levofloxacin 11 (0.93%) of 1179, ceftriaxone 14 (0.18%) of 7844, ciprofloxacin 0 (0%) of 545, and any fluoroquinolone 87 (0.94%) of 9264. Dysglycemia was more likely to occur in patients receiving any fluoroquinolone than in those receiving ceftriaxone (relative risk [RR] 3.32, 95% confidence interval (CI) 2.31-4.78, p < 0.05). The rate of dysglycemia did not differ with gatifloxacin and levofloxacin (RR 1.07, 95% CI 0.62-1.86, p = 0.8). Of the 101 patients with dysglycemias, hypoglycemia occurred in nine (9%) and hyperglycemia in 92 (91%). In a multivariate analysis of patients receiving fluoroquinolones, only concomitant sulfonylurea therapy was identified as an independent risk factor for development of hypoglycemia compared with patients who experienced hyperglycemia.

CONCLUSION

In the 17,108 patients receiving a fluoroquinolone or ceftriaxone, the rate of dysglycemia was greater in those receiving levofloxacin or gatifloxacin than in those receiving ceftriaxone. However, no difference was noted in the rate of glucose abnormalities with levofloxacin versus gatifloxacin. Clinicians should be aware of dysglycemic events that may occur in patients receiving fluoroquinolones, especially in those with diabetes mellitus or those receiving sulfonylureas.

Glucose Homeostasis Abnormalities Associated with Use of Gatifloxacin

BACKGROUND

More than 20 published case reports have described an association between the use of gatifloxacin and hypoglycemia or hyperglycemia. We compare the rates of glucose homeostasis abnormality (GHA) adverse event reports (AERs) associated with the use of gatifloxacin and comparator quinolones.

METHODS

We obtained spontaneous AERs associated with the use of ciprofloxacin, gatifloxacin, levofloxacin, and moxifloxacin from the US Food and Drug Administration that were reported between November 1997 and September 2003. We removed duplicate and foreign cases. We used specific coding terms to identify GHA AERs. We calculated GHA AER rates, using either the total number of AERs or estimated retail prescriptions as denominators.

RESULTS

The use of ciprofloxacin, gatifloxacin, levofloxacin, and moxifloxacin was associated with 10,025 unique AERs in the United States, including 568 GHA AERs, 25 of which had fatality. Use of gatifloxacin was associated with 453 GHA AERs (80%) and 17 GHA AERs with fatality (68%). GHA AERs comprised 24% of all AERs associated with gatifloxacin, compared with ciprofloxacin (1.3%), levofloxacin (1.6%), and moxifloxacin (1.3%) (P<.0001 for each comparison). Use of gatifloxacin was associated with 477 GHA AERs per 10(7) retail prescriptions, compared with ciprofloxacin (4 GHA AERs), levofloxacin (11 GHA AERs), and moxifloxacin (39 GHA AERs) (P<.0001 for each comparison). Patients with GHA AERs were older and more likely to be receiving concomitant treatment for diabetes. Limitations of the study include the use of spontaneous adverse event reporting, which is incomplete and potentially biased. This analysis cannot be used alone to demonstrate causality.

CONCLUSIONS

Use of gatifloxacin is associated with a much higher rate of GHA AERs than are comparator quinolones. This analysis is consistent with the results of in vitro analyses, animal studies, human volunteer studies, case reports, and a large randomized trial. Alternatives to gatifloxacin should be used in patients with diabetes.

Hypoglycemia in Inpatients After Gatifloxacin or Levofloxacin Therapy: Nested Case-Control Study

STUDY OBJECTIVES

To compare the incidence of hypoglycemic events in patients exposed to gatifloxacin or levofloxacin, and to measure the odds of experiencing a hypoglycemic event after receiving gatifloxacin versus levofloxacin while adjusting for confounders.

DESIGN

Nested case-control study within a historical cohort.

SETTING

A tertiary care, 730-bed, teaching hospital in central Illinois.

PATIENTS

Seven thousand two hundred eighty-seven hospitalized patients who received gatifloxacin or levofloxacin therapy.

MEASUREMENTS AND MAIN RESULTS

A total of 113 patients (case patients) had blood glucose levels below 51 mg/dl; 113 control patients, matched for age and sex, had no hypoglycemia. Matched conditional logistic regression models adjusted the odds of having hypoglycemia for significant covariates. The 12-month incidence of hypoglycemia was 11/1000 patients after levofloxacin administration and 21/1000 patients after gatifloxacin (absolute risk increase 10/1000 patients, 95% confidence interval [CI] 4-16/1000). Renal failure, sepsis syndrome, and concomitant hypoglycemic drug therapy significantly predicted hypoglycemia. After adjustment for significant predictors, the odds of having hypoglycemia were 2.81 (95% CI 1.02-7.70) times higher after gatifloxacin than levofloxacin therapy.

CONCLUSION

Among inpatients, the incidence of hypoglycemic events is greater after treatment with gatifloxacin than levofloxacin. The odds of experiencing hypoglycemic events are greater with gatifloxacin even after adjusting for other hypoglycemia risk factors, such as concomitant hypoglycemic drugs, renal failure, and sepsis syndrome.

Safety of Newer Parenteral Antibiotics

Several parenteral antimicrobials have been introduced into clinical practice over the course of the last decade. Some of these agents (e.g., linezolid, daptomycin, and tigecycline) are prototypes of new classes of compounds. In comparative clinical trials, these newer anti-infectives have been shown to be safe and to have low rates of discontinuation by patients. However, long-term use has revealed unique toxicities associated with the use of some of these drugs. The adverse events and potential drug interactions associated with the use of these antibiotics are variable and require familiarity with the safety profile of each drug. It is especially important that clinicians be able to recognize serious adverse events associated with the use of specific drugs, because most of the adverse events can be readily reversed by cessation of therapy.