Quinolones in the aged

Pharmacokinetic study of lascufloxacin in non-elderly healthy men and elderly men

We conducted this phase I clinical study to examine the pharmacokinetic profiles and safety of lascufloxacin (LSFX), a novel quinolone antibacterial agent, in non-elderly Japanese healthy men and the effects of aging on LSFX pharmacokinetics in elderly Japanese healthy men. 1. After single-dose oral administration of LSFX 100-800 mg (capsules) to six healthy adults in fasting state, the C_max and AUC_last roughly increased in proportion to the doses. 2. After multiple-dose oral administration of LSFX 75 mg (tablets) once daily for 7 days to six healthy adults, plasma LSFX reached the steady state by Day 7. The cumulative factor of LSFX on Day 7 to Day 1 was 1.65 for the C_max and 1.96 for the AUC_tau. 3. Regarding pharmacokinetic parameters of plasma LSFX after single-dose administration of LSFX 75 mg tablets (final product) to 24 healthy adults in fed state, the C_max was somewhat higher, 1.28 times more than that in fasting state, whereas no changes were found in the AUC_last. We therefore proposed that food effects of LSFX on absorption were negligible. 4. No clinically significant safety problems of LSFX were found in a series of studies involving healthy adults conducted this time. 5. After single-dose oral administration of LSFX 200 mg (capsules) to six elderly people in fasting state, its pharmacokinetic parameters were similar to those in non-elderly people, with no significant safety concerns. Therefore, adjustment of dosage and administration was considered to be unnecessary for LSFX administration to elderly individuals.

Antibiotic complications during the treatment of Mycobacterium ulcerans disease in Australian patients

BACKGROUND

Antibiotics are the recommended first-line treatment for Mycobacterium ulcerans disease. Antibiotic toxicity is common in Australian patients, yet antibiotic complication rates and their risk factors have not been determined.

AIM

To determine the incidence rate and risk factors for antibiotic toxicity in Australian patients treated for M. ulcerans disease.

METHODS

An analysis of severe antibiotic complications was performed using data from a prospective cohort of M. ulcerans cases managed at Barwon Health from 1 January 1998 to 30 June 2016. A severe antibiotic complication was defined as an antibiotic adverse event that required its cessation. Antibiotic complication rates and their associations were assessed using a Poisson regression model.

RESULTS

A total of 337 patients was included; 184 (54.6%) males and median age 57 years (interquartile range (IQR) 36-73 years). Median antibiotic treatment duration was 56 days (IQR 49-76 days). Seventy-five (22.2%) patients experienced severe antibiotic complications after a median 28 days (IQR 17-45 days) at a rate of 141.53 per 100 person-years (95% confidence interval (CI) 112.86-177.47). Eleven (14.7%) patients required hospitalisation. Compared with rifampicin/clarithromycin combinations, severe complication rates were not increased for rifampicin/ciprofloxacin (rate ratio (RR) 1.49, 95% CI 0.89-2.50, P = 0.13) or rifampicin/moxifloxacin (RR 2.54, 95% CI 0.76-8.50, P = 0.13) combinations, but were significantly increased for 'other' combinations (RR 2.53, 95% CI 1.13-5.68, P = 0.03). In a multivariable analysis, severe complication rates were significantly increased with reduced estimated glomerular filtration rates (EGFR) (adjusted rate ratio (aRR) 2.65, 95% CI 1.24-5.65 for EGFR 60-89 mL/min and aRR 1.31, 95% CI 0.49-3.53 for EGFR 0-59 mL/min compared with EGFR ≥90 mL/min, P < 0.01) and female gender (aRR 2.15, 95% CI 1.38-3.30, P < 0.01).

CONCLUSIONS

Severe antibiotic complications during M. ulcerans treatment are high with increased rates independently associated with reduced renal function and female gender.

Population Pharmacokinetics and Pharmacodynamics of Levofloxacin in Acutely Hospitalized Older Patients with Various Degrees of Renal Function

A retrospective study was conducted in a large sample of acutely hospitalized older patients who underwent therapeutic drug monitoring during levofloxacin treatment. The aim was to assess the population pharmacokinetics (popPK) and pharmacodynamics of levofloxacin among older patients. PopPK and Monte Carlo simulation were performed to define the permissible doses in older patients according to various degrees of renal function. Classification and regression tree (CART) analysis was used to detect the cutoff 24-hour area under the concentration-time curve (AUC24)/MIC ratio that best correlated with the clinical outcome. The probability of target attainment (PTA) of this value was calculated against different pathogens. A total of 168 patients were included, and 330 trough and 239 peak concentrations were used for the popPK analysis. Creatinine clearance (CrCL) was the only covariate that improved the model fit (levofloxacin CL = 0.399 + 0.051 × CrCLCKD-EPI [creatinine clearance estimated by means of the chronic kidney disease epidemiology]). Drug doses ranged between 500 mg every 48 h and 500 mg every 12 h in relation to different renal functions. The identified cutoff AUC24/MIC ratio (≥95.7) was the only covariate that correlated with a favorable clinical outcome in multivariate regression analysis (odds ratio [OR], 20.85; 95% confidence interval [CI], 1.56 to 186.73). PTAs were optimal (>80%) against Escherichia coli and Haemophilus influenzae, borderline against Staphylococcus aureus, and suboptimal against Pseudomonas aeruginosa The levofloxacin doses defined in our study may be effective for the treatment of infections due to bacterial pathogens, with an MIC of ≤0.5 mg/liter in older patients with various degrees of renal function, while minimizing the toxicity risk. Conversely, the addition of another active antimicrobial should be considered whenever treating infections caused by less susceptible pathogens.

The potential of antimicrobials to induce thrombocytopenia in critically ill patients: data from a randomized controlled trial

BACKGROUND

Antimicrobial-induced thrombocytopenia is frequently described in the literature among critically ill patients. Several antimicrobials have been implicated, although experimental evidence to demonstrate causality is limited. We report, using a randomized trial, the potential of antimicrobials to induce thrombocytopenia.

METHODS

Randomized trial allocated patients to antimicrobial treatment according to standard- of-care (SOC group) or drug-escalation in case of procalcitonin increases (high-exposure group). Patients were followed until death or day 28. Thrombocytopenia defined as absolute (platelet count ≤ 100 x 109/L) or relative (≥ 20% decrease in platelet count). Analyses were performed in the two randomized groups and as a merged cohort.

RESULTS

Of the 1147 patients with platelet data available, 18% had absolute thrombocytopenia within the first 24 hours after admission to intensive care unit and additional 17% developed this complication during follow-up; 57% developed relative thrombocytopenia during follow-up. Absolute and relative thrombocytopenia day 1-4 was associated with increased mortality (HR: 1.67 [95% CI: 1.30 to 2.14]; 1.71 [95% CI: 1.30 to 2.30], P<0.0001, respectively). Patients in the high-exposure group received more antimicrobials including piperacillin/tazobactam, meropenem and ciprofloxacin compared with the SOC group, whereas cefuroxime was used more frequently in the SOC group (p<0.05). Risk of absolute and relative thrombocytopenia (RR: 0.9 [0.7-1.3], p=0.7439; 1.2 [1.0-1.4], p=0.06; respectively), as well as absolute platelet count (daily difference, high-exposure vs. SOC -1.7 [-3.8-0.5], p=0.14) was comparable between groups. In observational analyses, use of ciprofloxacin and piperacillin/tazobactam predicted risk of relative thrombocytopenia (vs. cefuroxime, RR: 2.08 [1.48-2.92]; 1.44 [1.10-1.89], respectively), however only ciprofloxacin were associated with a reduction in absolute platelet count (p=0.0005).

CONCLUSION

High exposure to broad-spectrum antimicrobials does not result in a reduction in thrombocytopenia in critically ill patients. However, single use of ciprofloxacin, and less so piperacillin/tazobactam, may contribute to a lower platelet count.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00271752 http://clinicaltrials.gov/ct2/show/NCT00271752.

Levofloxacin-associated Achilles Tendon Rupture and Tendinopathy

Fluoroquinolones have a documented ability to induce Achilles tendinopathy. Hitherto, few published reports have implicated levofloxacin. This article reports 5 cases of Achilles tendon disorders, including 3 complicated by rupture of the tendon, during levofloxacin treatment of patients with chronic obstructive pulmonary disease.

Safety considerations of fluoroquinolones in the elderly: an update

The fluoroquinolones ciprofloxacin, levofloxacin, moxifloxacin and gemifloxacin are widely used for the treatment of various types of bacterial infections. Overall, these antibacterial agents can be considered safe and well tolerated drugs. Comparative studies have evaluated the use of quinolones in elderly and younger populations. Although age per se does not seem to decrease their tolerability, specific adverse effects of the quinolones must be considered when they are chosen for antibacterial treatment. Renal function declines consistently with age and doses of renally excreted quinolones (e.g. ofloxacin, levofloxacin, gatifloxacin) need to be adjusted if a clinically relevant reduction of creatinine clearance is identified. Reactions of the gastrointestinal tract, such as nausea, dyspepsia, vomiting or diarrhoea, are among the most often registered adverse drug reactions during therapy with fluoroquinolones. Treatment with a quinolone causes diarrhoea less frequently than treatment with other classes of antimicrobials. Conflicting data have been published with respect to the incidence of Clostridium difficile-associated diarrhoea in quinolone-treated patients. Hypersensitivity reactions, often manifested on the skin, occur less commonly during therapy with quinolones than, for example, during therapy with beta-lactam antibacterials. Adverse reactions of the CNS are of particular concern in the elderly population. Given the CNS excitatory effects of quinolones, elderly patients should be monitored carefully for such symptoms. It is likely that many signs of possible adverse reactions, such as confusion, weakness, loss of appetite, tremor or depression, are often mistakenly attributed to old age and remain unreported. Quinolones should be used with caution in patients with known or suspected CNS disorders that predispose to seizures (e.g. severe cerebral arteriosclerosis or epilepsy). Quinolones can cause QT interval prolongation. They should be avoided in patients with known prolongation of the QT interval, patients with uncorrected hypokalaemia or hypomagnesaemia and patients receiving class IA (e.g. quinidine, procainamide) or class III (e.g. amiodarone, sotalol) antiarrhythmic agents. Tendinitis and tendon ruptures are recognized as quinolone-induced adverse effects that can occur during treatment or as late as several months after treatment. Chronic renal diseases, concomitant use of corticosteroids and age >60 years are known risk factors for quinolone-induced tendopathies. Overall, the specific adverse-effect profile of quinolones must be considered when they are chosen for treatment of bacterial infections. Because of physiological changes in renal function and when certain co-morbidities are present, some special considerations are necessary when elderly patients are treated with these drugs.

Antimicrobial safety: focus on fluoroquinolones

BACKGROUND/PURPOSE

Infrequent toxicities associated with certain drugs and drug classes have recently gained much attention from different health-care perspectives. To protect the patient, continued surveillance of safety and tolerability data is essential. Data from preclinical testing, phase 1-3 trials, and postmarketing surveillance may be used to objectively assess the risks associated with a specific drug or family of compounds. This review summarizes safety and tolerability data for the quinolones.

MAIN FINDINGS

The most common adverse events associated with the quinolone class involve the gastrointestinal tract (nausea and diarrhea) and central nervous system (CNS) (headache and dizziness). These adverse events are usually mild and do not require discontinuation of therapy. Uncommon and potentially serious quinolone-related adverse events involve the cardiovascular system (rate-corrected electrocardiographic QT interval prolongation), musculoskeletal system (tendinitis and tendon rupture), endocrine system (glucose homeostasis dysregulation), renal system (crystalluria, interstitial nephritis, and acute renal failure), and the CNS (seizures). Severe idiosyncratic adverse events are specific to individual agents that may share some structural congruity, such as the 1-(2,4)-difluorophenyl group shared by trovafloxacin (associated with hepatitis), temafloxacin (associated with hemolytic-uremic syndrome), and tosufloxacin (associated with eosinophilic pneumonitis). Overall, discontinuation rates from clinical trials were <4% for the currently marketed quinolones. Quinolones with higher discontinuation rates, such as trovafloxacin (7.0%) and grepafloxacin (6.4%), are no longer available for general use.

CONCLUSIONS

The currently marketed quinolones are well tolerated, with safety profiles similar to those of other antimicrobial classes. Although adverse effects are unusual, some, including tendinitis and CNS-related effects, are more common with quinolones than with other antimicrobial classes. Rare adverse effects attributed to some members of the quinolone family (e.g., Torsades de Pointes, hepatotoxicity, and dysglycemias) are more likely to occur in select "susceptible" populations. These adverse events can often be circumvented by avoiding exposure to the specific quinolone. In some cases, the therapeutic value offered by a quinolone may outweigh its potential risks.

Efficacy and safety of gatifloxacin for urinary tract infection in nonspecialized Korean urologic practice

To investigate the efficacy and safety of gatifloxacin (400mg/day) on chronic prostatitis or cystitis, 453 patients with prostatitis (NIH category II or IIIa) (N=149, mean 45.8+/-13.3 years) and cystitis (N=304, mean 53.8+/-14.3 years) were enrolled. Total NIH CPSI score and symptom score for cystitis decreased from 20.3 to 9.9 (response rate 86.7%, 95% CI 80.2-93.2%) and from 6.2 to 1.8 (response rate 83.2%, 95% CI 78.7-87.7%), respectively. In the overall clinical efficacy, 71.2% and 88.4% of the patients with prostatitis and cystitis were responders, respectively. Of the patients, 15.7% reported insignificant adverse events. These results suggest that gatifloxacin was well tolerated and improved the clinical outcomes in patients with chronic prostatitis or cystitis.

Levofloxacin use in the elderly: focus on pneumonia

Levofloxacin is a broad-spectrum, rapid-acting bactericidal agent that exhibits concentration-dependent killing activity as well as a postantibiotic effect. Its activity includes enteric Gram-negative bacilli, Acinetobacter spp., Pseudomonas aeruginosa, methicillin-susceptible Staphylococcus aureus and most species of streptococci, including Streptococcus pneumoniae. With increasing age, there is a natural decline in renal function by approximately 1 ml/min/year after the age of 30 years, or an average decrease in creatinine clearance of 40% by the age of 80 years. This decline in renal function can have a significant impact on antibiotics that are predominantly eliminated from the body via the kidneys, such as levofloxacin. The favorable pharmacodynamic, safety and efficacy profiles, in addition to in vitro activity versus the usual respiratory pathogens, make levofloxacin among the first-line agents for the management of pneumonia, and an option for other respiratory bacterial infections in which more resistant organisms are a consideration, such as in the elderly population.

Quinolones in 2005: an update

Quinolones are one of the largest classes of antimicrobial agents used worldwide. This review considers the quinolones that are available currently and used widely in Europe (norfoxacin, ciprofloxacin, ofloxacin, levofloxacin and moxifloxacin) within their historical perspective, while trying to position them in the context of recent and possible future advances based on an understanding of: (1) their chemical structures and how these impact on activity and toxicity; (2) resistance mechanisms (mutations in target genes, efflux pumps); (3) their pharmacodynamic properties (AUC/MIC and Cmax/MIC ratios; mutant prevention concentration and mutant selection window); and (4) epidemiological considerations (risk of emergence of resistance, clonal spread). Their main indications are examined in relation to their advantages and drawbacks. Overall, it is concluded that these important agents should be used in an educated fashion, based on a careful balance between their ease of use and efficacy vs. the risk of emerging resistance and toxicity. However, there is now substantial evidence to support use of the most potent drug at the appropriate dose whenever this is required.

Retrospective analysis of the safety profile of oral moxifloxacin in elderly patients enrolled in clinical trials

BACKGROUND AND OBJECTIVE

As aging is associated with physiological changes, including renal and hepatic insufficiency, and a higher risk of drug interactions, special attention needs to be directed towards the safety of medications in the elderly. The objective of this analysis was to evaluate the safety of oral moxifloxacin in elderly patients who were enrolled in clinical trials and to compare these results to those of other commonly used antibacterials.

METHODS

Safety data from 27 prospective, randomised, comparative phase II/III trials of oral moxifloxacin included in the Bayer clinical trial database were pooled and analysed by age group (<65 years of age, 65-74 years of age, > or = 75 years of age) and by treatment group (moxifloxacin vs comparator). The primary endpoints included rates of treatment-emergent adverse events (all adverse events regardless of causality), drug-related adverse events, drug-related serious adverse events, deaths and premature discontinuations because of a treatment-emergent adverse event. A treatment by age group interaction test was used to determine if the comparison between moxifloxacin and the comparator group in the incidence rates of any treatment-emergent or drug-related adverse events were affected by increasing age.

RESULTS

Of the 12 231 patients who had valid safety data, 6270 had been treated with oral moxifloxacin and 5961 with a comparator antibacterial. The most frequently used comparators were cefuroxime and clarithromycin. Most patients (n = 9671) were <65 years of age (4939 moxifloxacin, 4732 comparator); 1636 patients were 65-74 years of age (842 moxifloxacin, 794 comparator); and 924 patients were > or = 75 years of age (489 moxifloxacin, 435 comparator). The treatment by age group interaction test revealed that the comparison of drug-related adverse event rates between the moxifloxacin and comparator group were not affected by increasing age (p = 0.43). Rates of premature termination between the moxifloxacin and comparator treatment groups also did not increase with age (p = 0.552). No arrhythmias related to corrected QT (QTc) interval prolongation were reported following oral moxifloxacin or comparator treatment in this large group of young and elderly patients. Overall, the number of deaths was similar between the treatment groups (17 moxifloxacin, 19 comparator).

CONCLUSIONS

Drug-related adverse event rates associated with oral moxifloxacin or the comparator therapy used in these studies did not significantly increase with advancing age. This pooled analysis suggests that oral moxifloxacin can be safely used in elderly patients with characteristics consistent with those enrolled into the clinical trials.

Fluoroquinolones for the treatment of outpatient community-acquired pneumonia

The increasing prevalence of beta-lactam and macrolide resistance in bacteria that cause respiratory infections has underscored the need for effective antimicrobial agents. The broad spectrum, excellent oral bioavailability, and once-daily dosing of fluoroquinolones contributed to the introduction of several new agents in the past decade. This class is among the world's most used antimicrobial therapies in community and hospital settings. Fluoroquinolones are generally well tolerated, but safety profiles differ widely among agents. Knowledge of in vitro activity, local microbiologic susceptibility and resistance patterns, adverse effects, and potential drug interactions should influence the selection of the best agent for individual patients. This overview of the fluoroquinolones directs particular attention to use in community-acquired pneumonia and safety.

Efficacy and safety of gatifloxacin in elderly outpatients with community-acquired pneumonia

To evaluate the safety and efficacy of gatifloxacin in adults <65, 65 to 79, or > or =80 years old with community-acquired pneumonia, adult male and female outpatients from general community-based practices were enrolled in an open-label, multicenter, noncomparative study. Gatifloxacin 400 mg once daily was administered for seven to 14 days. Medical history, physical examination, signs and symptoms of infection, Gram stain and culture if specimen available, clinical response, and safety were determined. Of 1655 treated patients, 1103 were at least 65 years old, 405 were 65 to 79, and 147 were at least 80. Patients > or =80 years old presented with chills, chest pain, fever, or headache less often than younger patients. Cure rates were 95.5% for patients <65 years old, 96.2% for those 65 to 79, and 90.2% for those at least 80 years old. Neither the frequency nor susceptibility of isolated pathogens appeared to differ with age. Between 93.7% and 100% of subsets of the two younger groups with verified Streptococcus pneumoniae or Hemophilus influenzae were cured. All oldest-group patients in the subset with verified S. pneumoniae and 71.4% (7) of patients with H. influenzae were cured. Each age group, including current or past smokers and patients receiving medications for concomitant conditions, tolerated treatment well. Gatifloxacin is safe and efficacious in adults of any age with community-acquired pneumonia, including the elderly up to 100 years old and patients with S. pneumoniae including penicillin-resistant strains.

Gatifloxacin in community-based treatment of acute respiratory tract infections in the elderly

The elderly are at increased risk for respiratory tract infections. To evaluate the safety and efficacy of gatifloxacin in adults of any age with community-acquired respiratory tract infections, this open-label, multicenter, noncomparative study in community-based practices enrolled male and female outpatients at least 18 years old with a clinical diagnosis of community-acquired pneumonia (CAP), acute-bacterial exacerbation of chronic bronchitis (AECB), or acute uncomplicated maxillary sinusitis. Gatifloxacin 400 mg was administered once daily for seven to 14 days. Of 14781 clinically evaluable patients, 2505 were at least 65 years old, 499, at lest 80. Cure rates for CAP, AECB, and sinusitis ranged from 91.6% to 95.5% for patients less than 65 years old, 91.1% to 96.2% for those 65 to 79 years of age, and 89.5% to 94.8% for those at least 80 years old. Each age group, including patients with concomitant cardiovascular or diabetic conditions, tolerated treatment well. Gatifloxacin is efficacious and well tolerated in adult outpatients of any age with respiratory tract infections and is an important therapeutic option, particularly in communities with a high prevalence of resistant pathogens.

Pharmacokinetics of levofloxacin during continuous venovenous hemodiafiltration and continuous venovenous hemofiltration in critically ill patients

STUDY OBJECTIVE

To assess the pharmacokinetics of levofloxacin during continuous venovenous hemodiafiltration (CVVHDF) and continuous venovenous hemofiltration (CVVH).

DESIGN

Nonrandomized pharmacokinetic evaluation.

SETTING

University surgical intensive care unit.

PATIENTS

Six critically ill patients.

INTERVENTION

Five patients received levofloxacin 500 mg/day and one patient received levofloxacin 125 mg/day All patients received continuous renal replacement therapy: CVVHDF on day 1 and CVVH on day 2, using an acrylonitrile hollow-fiber 0.9-m2 filter, constant blood flow rate of 90 ml/minute, substitution flow rate of 1 L/hour predilution, and dialysate flow rate of 1 L/hour (CVVHDF).

MEASUREMENTS AND MAIN RESULTS

Serum, ultrafiltrate, and dialysate concentrations of levofloxacin were determined by high-performance liquid chromatography. Extracorporeal clearance was 26.05 +/- 4.66 ml/hour during CVVHDF and 15.71 +/- 2.73 ml/hour during CVVH (p<0.05). Elimination half-life was 28.08 +/- 4.5 hours and 45.9 +/- 17.7 hours, and distribution volume was 1.51 +/- 0.52 L/kg and 1.42 +/- 0.42 L/kg for CVVHDF and CVVH, respectively. Saturation was 0.76 +/- 0.13 for CVVHDF versus a sieving coefficient of 0.77 +/- 0.16 for CVVH.

CONCLUSION

Marked extracorporeal elimination of levofloxacin occurs, requiring a dosage adjustment that can be calculated from the characteristics of CVVH and CVVHDF.

Safety and effectiveness of lomefloxacin in patients with acute exacerbation of chronic bronchitis (AECB) chronically treated with oral theophyllines

Lomefloxacin is a difluorinated quinolone with excellent activity against a wide range of pathogens including those responsible for acute exacerbations of chronic bronchitis (AECB). This open, cross-sectional, multicenter study has evaluated the efficacy and safety of a once-daily dosage of 400 mg lomefloxacin in patients with AECB chronically treated with theophylline. 137 patients (96 males, 41 females; mean age 66.1+/-11.2 yrs) were enrolled and 133 completed the study. 81% suffered from moderate AECB, 16% severe AECB. The clinical success rate was very high (95%), as well as the microbiological (93%). Side effects were scarce and were significant only in 3 patients, with 2 dropouts. All patients were using theophylline derivatives twice daily and continued without any variation in dosage during the lomefloxacin treatment. Theophylline plasma levels determined in 103 patients at baseline, during and at the end of the lomefloxacin treatment did not significantly change. We conclude that orally administered lomefloxacin at standard recommended dosage is well tolerated and effective in elderly patients with AECB. No dose adjustment is required even when it is co-administered with methylxanthines.

Effect of age and gender on the safety, tolerability, and pharmacokinetics of BAY 12-9566 in healthy subjects

The impact of age and gender on the single-dose pharmacokinetics, safety, and tolerability of BAY 12-9566 was evaluated in healthy subjects. Volunteers were grouped according to age and gender (13 young males, 11 elderly males, and 12 elderly females) and then randomized in a 2:1 ratio to receive a single oral 50 mg dose of BAY 12-9566 or placebo. Serial plasma samples were collected up to 336 hours postdose and assayed for BAY 12-9566. Peak plasma concentration, time to reach peak plasma concentration, the area under the concentration-time curve, oral clearance, volume of distribution, and elimination half-life were calculated. BAY 12-9566 was well tolerated in all treatment groups, and no serious adverse events occurred during the study. Substantial age- or gender-related differences were not observed for any of the pharmacokinetic parameters tested. Based on these pharmacokinetic and tolerability profiles, age- or gender-related dose adjustments were not required for BAY 12-9566.