Gatifloxacin: a review of its use in the management of bacterial infections

Recent efforts in the development of glycoconjugate vaccine and available treatment for tuberculosis

Tuberculosis (TB) continues to pose a grave threat to global health, despite relentless eradication efforts. In 1882, Robert Koch discovered that Mycobacterium tuberculosis (Mtb) is the bacterium responsible for causing tuberculosis. It is a fact that tuberculosis has claimed the lives of more than one billion people in the last few decades. It is imperative that we must take immediate and effective action to increase resources for TB research and treatment. Effective TB treatments demand an extensive investment of both time and finances, often requiring 6-9 months of rigorous antibiotic therapy. The most efficient way to control tuberculosis is by receiving a childhood Bacillus Calmette-Guérin (BCG) vaccination. Despite years of research on vaccine development, we still do not have any new approved vaccine for tuberculosis, except BCG, which is partially effective in young children. This review discusses briefly the available treatment for tuberculosis and remarkable advancements in glycoconjugate-based TB vaccine developments in recent years (2013-2024) and offers valuable direction for future research priorities.

Stimuli-Responsive Delivery of Antimicrobial Peptides Using Polyelectrolyte Complexes

Antimicrobial peptides (AMPs) are antibiotics with the potential to address antimicrobial resistance. However, their translation to the clinic is hampered by issues such as off-target toxicity and low stability in biological media. Stimuli-responsive delivery from polyelectrolyte complexes offers a simple avenue to address these limitations, wherein delivery is triggered by changes occurring during microbial infection. The review first provides an overview of pH-responsive delivery, which exploits the intrinsic pH-responsive nature of polyelectrolytes as a mechanism to deliver these antimicrobials. The examples included illustrate the challenges faced when developing these systems, in particular balancing antimicrobial efficacy and stability, and the potential of this approach to prepare switchable surfaces or nanoparticles for intracellular delivery. The review subsequently highlights the use of other stimuli associated with microbial infection, such as the expression of degrading enzymes or changes in temperature. Polyelectrolyte complexes with dual stimuli-response based on pH and temperature are also discussed. Finally, the review presents a summary and an outlook of the challenges and opportunities faced by this field. This review is expected to encourage researchers to develop stimuli-responsive polyelectrolyte complexes that increase the stability of AMPs while providing targeted delivery, and thereby facilitate the translation of these antimicrobials.

Versatile applications of transition metal incorporating quinoline Schiff base metal complexes: An overview

Since the last decade, research on quinoline Schiff base metal complexes has risen substantially due to their versatile applications across many significant fields. Schiff bases are also known as azomethines, aldimines, and imines. Quinoline Schiff base-derived metal complexes are intriguing to study topics. These complexes are employed in biological, analytical, and catalytic fields. Researchers have found that Schiff bases are more biologically active when coordinated with metal ions. Research in the biological sciences has shown that heterocyclic compounds like quinoline and its derivatives are important. Because of their broad spectrum of activity, quinoline derivatives have been discovered to be effective therapeutic agents for various disorders. Even though various classical synthetic pathways mentioned in the literature are still in use, there is an urgent need for a new, more effective method that is safer for the environment, has a higher yield, generates less hazardous waste, and is easier to use. This highlights the critical need for a safe, eco-friendly approach to quinoline scaffold synthesis. This review focuses exclusively on Schiff base metal complexes derived from quinoline, fabricated and studied in the past ten years, and having anticancer, antibacterial, antifungal, antioxidant, antidiabetic, antiproliferative, DNA-intercalation, and cytotoxic activities.

Different responses of representative denitrifying bacterial strains to gatifloxacin exposure in simulated groundwater denitrification environment

The impact of antibiotics on denitrification in the ecological environment has attracted widespread attention. However, the concentration threshold and inhibitory effect of the same antibiotic on denitrification mediated by mixed denitrifying microbes were conflicting in some studies. In this study, Paracoccus denitrificans, Acidovorax sp., and Pseudomonas aeruginosa were selected as representative denitrifying bacterial strains to explore the response of a single strain to gatifloxacin (GAT) exposure in groundwater denitrification. The results showed that the nitrate and nitrite removal efficiencies of Pseudomonas aeruginosa decreased by 34.87-36.25 % and 18.27-23.31 %, respectively, with exposure to 10 μg/L GAT, accompanied by a significant decline in denitrifying enzyme activity and gene expression. In contrast, the elevated denitrifying enzyme activity and gene expression of Paracoccus denitrificans promoted its nitrate and nitrite reduction by 2.09-10.00 % and 0-8.44 %, respectively. Additionally, there were no obvious effects on the removal of nitrate and nitrite by Acidovorax sp. in the presence of 10 μg/L GAT, which was consistent with the variation in denitrifying enzyme activity and total gene expression levels. The fit results of the Monod equation and its modification further elucidated the nitrate degradation characteristics from the perspective of denitrification kinetics. Furthermore, antibiotic resistance gene (ARG) analysis showed that the addition of 10 μg/L GAT (approximately 30 days) did not observably increase the relative abundance of ARGs. This study provides some preliminary understanding of the response differences of representative denitrifying bacterial strains to antibiotic exposure in groundwater denitrification.

Status of Physicochemical and Microbiological Analytical Methods of Gatifloxacin: A Review

Background

Gatifloxacin (GAT), an antimicrobial of the fourth generation of fluoroquinolones, has a broad spectrum of action with activity against Gram-positive and Gram-negative, aerobic and anaerobic organisms, including mycobacteria.

Objective

The objective of this review is to discuss about (i) characteristics, (ii) properties, and (iii) analytical methods of gatifloxacin.

Results

Among the methods described in the literature for the evaluation of GAT, the most frequent was HPLC (50%) for both the analysis of pharmaceutical and biological matrixes. GAT has no monograph described in official compendia. Methods for evaluating GAT in pharmaceutical matrixes were the most found in the literature, 79%. Acetonitrile (42%), methanol (20%), and buffer solution (16%) were the most used diluents. GAT, being an antimicrobial, must be analyzed by physical-chemical and microbiological methods, since the evaluation of potency is essential. In this context, the literature is scarce (4%).

Conclusions

There is a gap in the literature for environmentally friendly methods for evaluating GAT. Faster, more optimized and dynamic microbiological methods, as well as physicochemical methods, use less aggressive solvents with fewer steps and less waste. Currently, pharmaceutical analyses require reliable analytical methods, but also safe for both the analyst and the environment.

Highlights

This review shows the status of analytical methods, both physicochemical and microbiological, for the analysis of GAT in pharmaceutical and biological matrixes, also addressing its context in green and sustainable analytical chemistry.

Advantages of Cubosomal Formulation for Gatifloxacin Delivery in the Treatment of Bacterial Keratitis: In Vitro and In Vivo Approach Using Clinical Isolate of Methicillin-Resistant Staphylococcus aureus

The objective of this study was to enhance the corneal permeation of gatifloxacin (GTX) using cubosomal nanoparticle as a delivery system. Cubosomal nanoparticle loaded with GTX was prepared and subjected for in vitro and in vivo investigations. The prepared GTX-loaded cubosomal particles exhibited nanoparticle size of 197.46 ± 9.40 nm and entrapment efficiency of 52.8% ± 2.93. The results of ex vivo corneal permeation of GTX-loaded cubosomal dispersion show approximately 1.3-fold increase compared to GTX aqueous dispersion. The incorporation of GTX into cubosomal particles resulted in a fourfold reduction in the minimum inhibitory concentration (MIC) value for the GTX cubosomal particles relative to GTX aqueous dispersion. Furthermore, the enhanced corneal penetration of GTX-loaded cubosomal dispersion compared was evident by a significant decrease in the area % of corneal opacity in MRSA infected rats. Moreover, these results were confirmed by photomicrographs of histological structures of corneal tissues from rats treated with GTX-cubosomal dispersion which did not present any change compared to that of the normal rat corneas. In conclusion, treatment of ocular bacterial infections and reduction in the probability of development of new resistant strains of MRSA could be accomplished with GTX-loaded cubosomal nanoparticles.

Fourth-Generation Antibiotic Gatifloxacin Encapsulated by Microemulsions: Structural and Probing Dynamics

To overcome the increased disease rate, utilization of the versatile broad spectrum antibiotic drugs in controlled drug-delivery systems has been a challenging and complex consignment. However, with the development of microemulsion (μE)-based formulations, drugs can be effectively encapsulated and transferred to the target source. Herein, two biocompatible oil-in-water (o/w) μE formulations comprising clove oil/Tween 20/ethylene glycol/water (formulation A) and clove oil/Tween 20/1-butanol/water (formulation B) were developed for encapsulating the gatifloxacin (GTF), a fourth-generation antibiotic. The pseudoternary phase diagrams were mapped at a constant surfactant/co-surfactant (1:1) ratio to bound the existence of a monophasic isotropic region for as-formulated μEs. Multiple complementary characterization techniques, namely, conductivity (σ), viscosity (η), and optical microscopy analyses, were used to study the gradual changes that occurred in the microstructure of the as-formulated μEs, indicating the presence of a percolation transformation to a bicontinuous permeate flow. GTF showed good solubility, 3.2 wt % at pH 6.2 and 4.0 wt % at pH 6.8, in optimum μE of formulation A and formulation B, respectively. Each loaded μE formulation showed long-term stability over 8 months of storage. Moreover, no observable aggregation of GTF was found, as revealed by scanning transmission electron microscopy and peak-to-peak correlation of IR analysis, indicating the stability of GTF inside the formulation. The average particle size of each μE, measured by dynamic light scattering, increased upon loading GTF, intending the accretion of drug in the interfacial layers of microdomains. Likewise, fluorescence probing sense an interfacial hydrophobic environment to GTF molecules in any of the examined formulations, which may be of significant interest for understanding the kinetics of drug release.

Silver nanoparticles enhanced flow injection chemiluminescence determination of gatifloxacin in pharmaceutical formulation and spiked urine sample

Silver nanoparticles have been utilized for the enhanced chemiluminogenic estimation of fluoroquinolone antibiotic gatifloxacin. It has been found that the weak chemiluminescence intensity produced from the reaction between calcein and KMnO4 can further be strengthened by the addition of silver nanoparticles in the presence of gatifloxacin. This phenomenon has been exploited to the quantitative determination of gatifloxacin. Under the optimum experimental conditions, the calibration curves are linear over the range of 8.9×10(-9)-4.0×10(-6) M, while the limits of detections were found to be 2.6×10(-9) M with correlation coefficient value (r(2)) 0.9999. The relative standard deviation calculated from six replicate measurements (1.0×10(-4) M gatifloxacin) was 1.70%. The method was applied to pharmaceutical preparations and the results obtained were in reasonable agreement with the amount labeled on the formulations. The proposed method was also used for the determination of gatifloxacin in spiked urine samples with satisfactory results. No interference effects from some common excipients used in pharmaceutical preparations have been found.

Evaluation of gatifloxacin pluronic micelles and development of its formulation for ocular delivery

The purpose of the present study was to enhance the solubility of gatifloxacin by developing self-assembling pluronic micelles of gatifloxacin for ocular delivery, to overcome the problem of poor bioavailability and therefore lesser therapeutic response exhibited by conventional ophthalmic solutions of the drug. Gatifloxacin was loaded in micelles by solid dispersion method using Pluronic F127 and evaluated for particle size, drug loading, loading efficiency, in vitro transcorneal permeation study, in vitro drug release, solubility studies, microbiological studies, ex vivo mucoadhesive strength, and ocular safety studies. The drug loading and drug loading efficiency studies revealed that gatifloxacin/Pluronic F127 ratio of 0.25/2.52 g offered good drug loading (9.96 %), high loading efficiency (90 %), and acceptable particle size of 176 nm (polydispersity index 0.345). Hen's egg test chorioallantoic membrane (HET-CAM) assay with 0 score in 8 h and ocular safety test with score of 2 indicate the nonirritant property of the developed pluronic micelles. In vitro transcorneal permeation studies through excised goat cornea indicated increase in ocular availability with no corneal damage. In vitro drug release data of optimized formulation provided sustained release over a period of 8 h. Optimized formulation was found to possess acceptable transcorneal permeation and antimicrobial efficacy when compared to marketed eye drops. The solubility studies of gatifloxacin from these lyophilized pluronic micelles revealed 18.67-fold increase in comparison to gatifloxacin suspension in water. The pluronic micelles could enhance ocular bioavailability of gatifloxacin, prolong its residence time in the eyes, and may lead to reduced instillation frequency, thereby resulting in better patient compliance.

Cefepime

Cefepime (Maxipime), Maxcef, Cepimax, Cepimex, Axepim, a parenteral fourth-generation cephalosporin, is active against many organisms causative in pneumonia. Cefepime has in vitro activity against Gram-positive organisms including Staphylococcus aureus and penicillin-sensitive, -intermediate and -resistant Streptococcus pneumoniae similar to that of cefotaxime and ceftriaxone. Cefepime also has good activity against Gram-negative organisms, including Pseudomonas aeruginosa, similar to that of ceftazidime. Importantly, cefepime is stable against many of the common plasmid- and chromosome-mediated beta-lactamases and is a poor inducer of AmpC beta-lactamases. As a result, it retains activity against Enterobacteriaceae that are resistant to third-generation cephalosporins, such as derepressed mutants of Enterobacter spp. Cefepime may be hydrolyzed by the extended-spectrum beta-lactamases produced by some members of the Enterobacteriaceae, but to a lesser extent than the third-generation cephalosporins. Monotherapy with cefepime 1 or 2g, usually administered intravenously twice daily, was as effective for clinical and bacteriological response as ceftazidime, ceftriaxone or cefotaxime monotherapy (1 or 2g two or three times daily) in a number of randomized, clinical trials in hospitalized adult, or less commonly, pediatric, patients with generally moderate to severe community-acquired or nosocomial pneumonia. More limited data indicated that monotherapy with cefepime 2g three times daily was also as effective in treating patients with nosocomial pneumonia as imipenem/cilostatin 0.5g four times daily, and when combined with amikacin, cefepime was as effective as ceftazidime plus amikacin. Patients with pneumonia who failed to respond to previous antibacterial therapy with penicillins or other cephalosporins responded to treatment with cefepime. Cefepime is generally well tolerated, with a tolerability profile similar to those of other parenteral cephalosporins. In clinical trials, the majority of adverse events experienced by cefepime recipients were mild to moderate and reversible. The most common adverse events with a causal relationship to cefepime reported in clinical trials included rash and diarrhea. Other, less common, adverse events included pruritus, urticaria, nausea, vomiting oral candidiasis, colitis, headache, fever, erythema and vaginitis.

CONCLUSION

Cefepime is an established and generally well tolerated parenteral drug with a broad spectrum of antibacterial activity which, when administered twice daily, provides coverage of most of the pathogens that may be causative in pneumonia. In randomized clinical trials in hospitalized patients with generally moderate to severe community-acquired or nosocomial pneumonia, cefepime monotherapy exhibited good clinical and bacteriological efficacy. Cefepime may become a preferred antibacterial agent for infections caused by Enterobacter spp. With prudent use in order to prevent the emergence of resistant organisms, cefepime will continue to be a suitable option for the empiric treatment of pneumonia.

Ultrasensitive study of gatifloxacin based on its enhancing effect on the cerium (IV)-sodium hyposulfite chemiluminescence reaction in a micellar medium

A sensitive and rapid flow-injection chemiluminescence (CL) method has been developed for the determination of gatifloxacin in pharmaceutical preparations and biological samples. The method is based on the enhancing effect of gatifloxacin on CL emission generated by the interaction of Ce (IV) in sulphuric acid and sodium hyposulphite (Na(2)S(2)O(4)) sensitized by sodium dodecyl benzene sulfonate (SDBS). Strong CL emission was observed when gatifloxacin was injected into the Ce (IV) in sulphuric acid and Na(2)S(2)O(4) solution incorporated with SDBS in a flow-cell. Several experimental parameters affecting the CL reaction were investigated and optimized systematically. Under the optimum conditions, it was found that the CL intensity is proportional to the concentration of gatifloxacin in the range of 1.12 × 10(-11)-4.40 × 10(-9) g mL(-1) with a co-relation coefficient of 0.9994. The limit of detection was found to be 4.87 × 10(-12) g mL(-1) and the relative standard deviation (RSD, n=7) was 1.8% for 4 × 10(-8) g mL(-1) of GFLX. The proposed method offers higher sensitivity, wide linear range and better stability without requiring sophisticated instrumentation. Thus, the proposed method has been successfully applied to the determination of gatifloxacin in pharmaceuticals, serum and human urine.

Optimization of gatifloxacin liposomal hydrogel for enhanced transcorneal permeation

The aim of this study was to prepare and characterize a topically effective prolonged-release ophthalmic gatifloxacin liposomal hydrogel formulation. Reverse-phase evaporation was used for the preparation of liposomes consisting of phosphatidylcholine (PC) and cholesterol (CH). The effect of PC:CH molar ratio on the percentage of drug encapsulated was investigated. The effect of additives, such as stearylamine (SA) or dicetyl phosphate (DP), as positive and negative charge inducers, respectively, was studied. Morphology, mean size, encapsulation efficiency, and in vitro release of gatifloxacin from liposomes were evaluated. For hydrogel preparation, carbopol 940 was applied. In vitro transcorneal permeation through excised albino rabbit cornea was also determined. Optimal encapsulation efficiency was found at the 5:3 PC:CH molar ratio; by increasing CH content above this limit, the encapsulation efficiency decreased. Positively charged liposomes showed superior entrapment efficiency over other liposomes. Hydrogel-containing liposomes with lipid content PC, CH, and SA in a molar ratio of 5:3:1, respectively, showed best release and transcorneal permeation. These results suggest that the encapsulation of gatifloxacin into liposomes prolonged the in vitro release, depending on composition of the vesicles. In addition, the polymer hydrogel used in the preparation ensured steady, prolonged transcorneal permeation. In conclusion, gatifloxacin liposomal hydrogel is a suitable delivery system for the improvement of the ocular bioavailability of gatifloxacin.

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.

Pharmacokinetics of gatifloxacin after a single oral dose in healthy young adult subjects and adult patients with chronic bronchitis, with a comparison of drug concentrations obtained by bronchoscopic microsampling and bronchoalveolar lavage

BACKGROUND

Bronchoalveolar lavage (BAL) is an established technique for measuring antibiotic concentrations in the epithelial lining fluid (ELF) of the bronchiolar and alveolar regions; however, the results may not reflect concentrations in bronchial regions. Bronchoscopic microsampling (BMS) is a technique that makes it possible to obtain multiple samples from bronchial ELF.

OBJECTIVE

BMS and BAL were used to analyze the pharmacokinetics of gatifloxacin in bronchial ELF from healthy young adult subjects and adult patients with chronic bronchitis.

METHODS

Bronchial ELF samples were obtained by BMS at 1, 2, 3, 4, 6, 10, and 24 hours after administration of a single oral dose of gatifloxacin 200 mg in healthy young adult (aged 20-25 years) subjects, and at 1, 2, 4, and 10 hours after a single dose in patients with chronic bronchitis (aged > or =20 years). At least 1 month after the initial BMS, alveolar (BAL) and bronchial (BMS) ELF samples were obtained from another group of healthy subjects 2 hours after administration of a single oral dose of gatifloxacin 200 mg for comparison of gatifloxacin concentrations in samples obtained by the 2 techniques.

RESULTS

Bronchial ELF samples were obtained from 8 healthy subjects and 5 patients with chronic bronchitis; alveolar ELF samples were obtained from a separate group of 5 healthy subjects. For the healthy subjects, the mean (SD) AUC(0-24) in serum and bronchial ELF, corrected for mg/kg doses, was 4.6 (1.1) and 7.6 (3.5) mg x h/L, respectively. In the patients with chronic bronchitis, the AUC(0-10) in serum and bronchial ELF, corrected for mg/kg doses, was 3.9 (0.8) and 4.1 (1.5) mg x h/L. The C(max) in serum and bronchial ELF, corrected for mg/kg doses, was 0.6 (0.2) and 1.4 (0.8) mg/L in healthy subjects and 0.7 (0.2) and 0.7 (0.2) mg/L in patients with chronic bronchitis. In healthy subjects, the C(max) and AUC(0-24) were significantly higher in bronchial ELF than in serum (both, P < 0.05). Gatifloxacin concentrations were significantly lower in bronchial ELF obtained by BMS than in alveolar ELF obtained by BAL (P < 0.05).

CONCLUSIONS

Based on the findings of this study in small numbers of healthy young adult volunteers and patients with chronic bronchitis, BMS appears to be a promising method for measuring drug concentrations and determining the pharmacokinetic profile of gatifloxacin in bronchial ELF. Additional studies are needed to correlate measured concentrations obtained by BMS with clinical and/or microbiologic outcomes in larger populations.

Plasma Concentrations, Pharmacokinetics and Urinary Excretion of Gatifloxacin after Single Intravenous Injection in Buffalo Calves

The pharmacokinetics and urinary excretion of gatifloxacin were investigated after a single intravenous injection of 4 mg/kg body weight in buffalo calves. The therapeutic plasma drug concentration was maintained for up to 12 h. Gatifloxacin rapidly distributed from blood to tissue compartments, which was evident from the high values of the distribution rate constant, alpha1 (11.1 +/- 1.06 h(-1)) and the rate constant of transfer of drug from central to peripheral compartment, k12 (6.29 +/- 0.46 h(-1)). The area under the plasma drug concentration-time curve and apparent volume of distribution were 17.1 +/- 0.63 (microg.h)/ml and 3.56 +/- 0.95 L/kg, respectively. The elimination half-life (t (1/2 beta)), total body clearance (ClB) and the ratio of drug present in tissues and plasma (T/P) were 10.4 +/- 2.47 h, 235.1 +/- 8.47 ml/(kg.h) and 10.1 +/- 2.25, respectively. About 19.7% of the administered drug was excreted in urine within 24 h. A satisfactory intravenous dosage regimen for gatifloxacin in buffalo calves would be 5.3 mg/kg at 24 h intervals.

Stability indicating high-performance thin-layer chromatographic determination of gatifloxacin as bulk drug and from polymeric nanoparticles

A simple, sensitive, selective, precise and stability indicating high-performance thin-layer chromatographic method for determination of gatifloxacin both as a bulk drug and from polymeric nanoparticles was developed and validated as per the International Conference on Harmonization (ICH) guidelines. The method employed thin-layer chromatography (TLC) aluminium plates precoated with silica gel 60F-254 as the stationary phase and the mobile phase consisted of n-propanol-methanol-concentrated ammonia solution (25%) (5:1:0.9, v/v/v). This solvent system was found to give compact spots for gatifloxacin (R(f) value of 0.60+/-0.02). Densitometric analysis of gatifloxacin was carried out in the absorbance mode at 292 nm. The linear regression analysis data for the calibration plots showed good linear relationship with r=0.9953 with respect to peak area in the concentration range of 400-1200 ng spot(-1). The mean value (+/-S.D.) of slope and intercept were 9.66+/-0.05 and 956.33+/-27.67, respectively. The method was validated for precision, accuracy, ruggedness and recovery. The limits of detection and quantitation were 2.73 and 8.27 ng spot(-1), respectively. Gatifloxacin was subjected to acid and alkali hydrolysis, oxidation, photodegradation and dry heat treatment. The drug undergoes degradation under acidic and basic conditions and upon wet and dry heat treatment. The degraded products were well separated from the pure drug. The statistical analysis proves that the developed method for quantification of gatifloxacin as bulk drug and from polymeric nanoparticles is reproducible and selective. As the method could effectively separate the drug from its degradation products, it can be employed as stability-indicating one.

Effect of formulation factors on in vitro transcorneal permeation of gatifloxacin from aqueous drops

The purpose of this research was to optimize the formulation factors for maximum in vitro permeation of gatifloxacin from aqueous drops through excised goat cornea and to evaluate the permeation characteristics of drug from selected marketed eyedrop formulations. Permeation studies were conducted by putting 1 mL of formulation on the cornea (0.67 cm(2)) fixed between the donor and receptor compartments of an all-glass modified Franz diffusion cell and measuring gatifloxacin concentration in the receptor (containing normal saline under stirring) by spectrophotometry at 291.5 nm, after 120 minutes. Raising the drug concentration of the drops increased the drug permeation but decreased the percent permeation and the in vitro ocular availability. Raising the pH of the formulation from pH 5 to 7.2 increased both the drug permeation and the in vitro ocular availability. Eyedrops containing benzalkonium chloride (BAK; 0.01% wt/vol) and disodium edetate (EDTA; 0.01% wt/vol) showed maximum permeation, followed by Zymar, BAK (0.01% wt/vol), Gatilox, Gatiquin, and Gate (statistically significant P < .05 compared with control). In vitro titration of the formulations with 0.1N NaOH indicated the presence of a buffer in Zymar (pH 6) and Gate (pH 5.8), which may cause irritation and induce lacrimation, resulting in reduced ocular availability in vivo. Thus, formulation with BAK and EDTA, which is unbuffered, has a better likelihood of being absorbed in vivo. The BAK-EDTA formulation significantly (P < .05) increased the permeation of gatifloxacin through paired excised corneas of goat, sheep, and buffalo, compared with the control formulation. The goat cornea showed the greatest increase in permeation, followed by the sheep and buffalo corneas.

Determination of Gatifloxacin and Ornidazole in Tablet Dosage Forms by High-Performance Thin-Layer Chromatography

A simple and sensitive high-performance thin-layer chromatography (HPTLC) method has been developed for the quantitative estimation of gatifloxacin and ornidazole in its combined dosage forms. Gatifloxacin and ornidazole were chromatographed on silica Gel 60 F(254) TLC plate using n-butanol:methanol:ammonia (6 M) (8:1:1.5 v/v) as the mobile phase and scanned at 302 nm using a Camag TLC Scanner 3. The R(f) value of gatifloxacin and ornidazole was found to be 0.21 +/- 0.02 and 0.76 +/- 0.04, respectively. The linearity of gatifloxacin and ornidazole were in the range of 100 - 500 ng/spot and 250 - 1250 ng/spot, respectively. The limit of detection was found to be 40 ng/spot for gatifloxacin and 100 ng/spot for ornidazole. The proposed method was applied for the determination of gatifloxacin and ornidazole in combined dosage forms.

Gatifloxacin: a review of its use in the treatment of bacterial infections in the US

Gatifloxacin (Tequin) is an 8-methoxy fluoroquinolone approved in the US for use in the treatment of community-acquired pneumonia (CAP), acute exacerbations of chronic bronchitis (AECB), acute sinusitis, uncomplicated and complicated urinary tract infections (UTIs), pyelonephritis, gonorrhoea and uncomplicated skin and skin structure infections. Gatifloxacin has a broad spectrum of antibacterial activity in vitro and good clinical and bacteriological efficacy in patients with indicated infections following once-daily administration by the intravenous or oral routes. It is generally well tolerated; the most common adverse events are associated with the gastrointestinal tract and CNS. Recent approvals for the use of gatifloxacin in the treatment of CAP due to multidrug-resistant Streptococcus pneumoniae (MDRSP) and in uncomplicated skin and skin structure infections extend the role of this drug in the treatment of bacterial infections in the US.

Randomized, investigator-blinded, multicenter, comparative study of gatifloxacin versus amoxicillin/clavulanate in recurrent otitis media and acute otitis media treatment failure in children

BACKGROUND

Recurrent otitis media and acute otitis media treatment failure are commonly encountered in the pediatric population.

OBJECTIVE

To compare the clinical efficacy of gatifloxacin with amoxicillin/clavulanate for the treatment of acute otitis media treatment failure and recurrent otitis media.

METHODS

Three hundred fifty-four children 6 months-7 years with recurrent otitis media and/or acute otitis media failure were stratified according to age (younger than 2 years versus 2 years or older) and then randomly assigned to 10 days of treatment with gatifloxacin 10 mg/kg once daily or amoxicillin/clavulanate 90 mg/6.4 mg in 2 divided doses. Tympanocentesis was performed in 116 children with acute otitis media treatment failure and 52 with recurrent otitis media at study entry to validate the clinical diagnosis and provide microbiologic data. The primary outcome measure was clinical resolution of infection at the test-of-cure visit 3-10 days after completing treatment.

RESULTS

Clinical resolution of acute otitis media was observed in 79.0% (49 of 62) of clinically evaluable children younger than 2 years and 90.3% (56 of 62) of those 2 years or older who were treated with gatifloxacin as compared with 77.6% (45 of 58) of children younger than 2 years and 79.7% (47 of 59) of children 2 years or older treated with amoxicillin/clavulanate. In patients with acute otitis media treatment failure, clinical response rates for children younger than 2 years and those 2 years or older were 87.5% (21 of 24) and 97.0% (32 of 33) with gatifloxacin versus 63.6% (14 of 22) and 83.9% (26 of 31) with amoxicillin/clavulanate. The corresponding clinical response rates in patients with recurrent otitis media were 79.2% (19 of 24) and 85.7% (18 of 21) with gatifloxacin and 90.5% (19 of 21) and 76.0% (19 of 25) with amoxicillin/clavulanate. Clinical success in those subjects having pretreatment middle ear fluid pathogens was similar for the 2 regimens [80.0% (24 of 30) gatifloxacin, 77.1% (27 of 35) amoxicillin/clavulanate]. Emergence of fluoroquinolone-resistant strains was not observed. Both drugs were generally well-tolerated. Diarrhea was the most common drug-related adverse event (10% gatifloxacin, 18% amoxicillin/clavulanate). No evidence of abnormal joint or gait findings was found during a 12-month follow-up.

CONCLUSIONS

Gatifloxacin once daily is at least as effective and well-tolerated as amoxicillin/clavulanate twice daily in children with acute otitis media treatment failure or recurrent otitis media. There was no evidence of arthrotoxicity or emergence of fluoroquinolone-resistant bacteria in gatifloxacin-treated children.

Gatifloxacin in community-acquired respiratory tract infection

Gatifloxacin (Tequin, Kyorin Pharmaceutical Co. Ltd) is a new fluoroquinolone with a broad spectrum of activity for pathogens implicated in community-acquired respiratory tract infections, including Gram-positive, -negative and atypical bacteria. Excellent oral bioavailability, a half-life allowing once-daily administration and excellent penetration into respiratory tissues are desirable pharmacokinetic characteristics of gatifloxacin. Monte Carlo simulation of gatifloxacin in Streptococcus pneumoniae infection demonstrates that adequate levels of pharmacokinetic/pharmacodynamic parameters are obtained with gatifloxacin in almost all instances. In randomised, controlled trials and a large open-label, community-based study, gatifloxacin has shown excellent clinical and bacteriological efficacy in acute bacterial sinusitis, acute exacerbations of chronic bronchitis and community-acquired pneumonia. Current guidelines recommend the initial empiric use of gatifloxacin (along with the other new fluoroquinolones) for community-acquired respiratory tract infection in patients who have increased likelihood of infection with resistant pathogens. Another group of patients where this agent is recommended for initial antimicrobial therapy are those who, because of underlying disease and/or comorbid conditions, need an antibiotic with high antimicrobial efficacy to achieve optimal outcomes.

Coadministration of Gatifloxacin and Multivitamin Preparation Containing Minerals: Potential Treatment Failure in an Elderly Patient

OBJECTIVE:

To report a case of probable treatment failure in a patient receiving gatifloxacin and a multivitamin preparation containing minerals.

CASE SUMMARY:

A 77-year-old white woman was prescribed gatifloxacin for hospital-acquired bacterial pneumonia. She was also receiving calcium carbonate 500 mg twice daily and a multivitamin preparation containing minerals once a day. Three days after gatifloxacin was started, the patient was still febrile, coughing, and not responding clinically. It was noted that nurses were administering the gatifloxacin tablet at the same time as the multivitamin tablet. The time of administration for gatifloxacin was changed to 6 hours after the patient received her multivitamin preparation. Two days later, she clinically improved.

DISCUSSION:

Studies have shown that the bioavailability of gatifloxacin is decreased with concurrent administration of antacids containing aluminum or magnesium; dietary supplements containing zinc, magnesium, and iron; multivitamin preparations containing minerals; and sucralfate. An objective causality assessment revealed that the adverse drug effect was probable.

CONCLUSIONS:

This case illustrates the need to recognize this potential interaction and to know how to avoid possible treatment failure.

Urinary bactericidal activity, urinary excretion and plasma concentrations of gatifloxacin (400 mg) versus ciprofloxacin (500 mg) in healthy volunteers after a single oral dose

In an open randomised double-crossover study 12 volunteers (six men, six women) received a single oral dose of gatifloxacin (400 mg) or ciprofloxacin (500 mg) to assess urinary bactericidal activity (in eight intervals up to 120 h) and pharmacokinetic (PK) parameters (up to 36 h). Plasma concentrations and urinary excretion were determined by HPLC with fluorescence detection, and urinary bactericidal titers (UBT) by microdilution-method, using antibiotic-free urine of each volunteer. The mean maximum plasma concentration of gatifloxacin was 3.35 mg/l and that of ciprofloxacin 2.12 mg/l. The mean (median) cumulative renal excretion of the parent drug was for gatifloxacin 81 (83)% of the administered dose within 120 h and for ciprofloxacin 43 (45)%. The UBTs, i.e. the highest two-fold dilution (antibiotic-free urine as diluent) of urine still being bactericidal, were determined for an Escherichia coli ATCC reference strain and nine clinical uropathogens with the following MICs (mg/l) for gatifloxacin/ciprofloxacin (microdilution, MHB): E. coli ATCC 25922 (0.008/0.008); E. coli 523 (0.06/0.06); Klebsiella pneumoniae 1058 (0.03/0.016); Proteus mirabilis 524 (0.125/0.016); Pseudomonas aeruginosa 561 (1/0.125); Enterococcus faecalis strains 60 an 55 (0.5/1 and 8/32); Staphylococcus aureus strains 248 and 596 (both 0.03/0.125) and S. saprophyticus Ho94 (0.125/0.25). The median UBTs measured within the first 6h for gatifloxacin were between 1:16 and 1:>or=1024 for the Gram-negative strains including P. aeruginosa and between 1:8 and 1:>or=1024 for the five Gram-positive strains. The median UBTs for ciprofloxacin were between 1:64 and 1:>or=1024 for the Gram-negative strains (incl P. aeruginosa) and between 1:1.5 and 1:768 for the five Gram-positive strains. The UBTs up to 12 < 0.05 h showed no difference (P<0.05 ) for both E. coli strains, but ciprofloxacin was superior to gatifloxacin against Klebsiella, Proteus and Pseudomonas strains and gatifloxacin was superior to ciprofloxacin against all Gram-positive strains. For the UBTs at 12-24 h, gatifloxacin was generally superior to ciprofloxacin, but showed no difference in the Proteus and Pseudomonas strains. The areas under the UBT-time-curve (AUBT) up to 120 h showed statistically significant (P ) differences between both quinolones in favour of gatifloxacin against 8 of 10 strains tested, no difference for P. mirabilis and significantly higher activity of ciprofloxacin against P. aeruginosa. In conclusion, gatifloxacin and ciprofloxacin had overall comparable initial urinary bactericidal activity with some differences for specific pathogens, some times in favour of gatifloxacin (Gram-positives) and some times of ciprofloxacin (usually Gram-negatives), suggesting that for empiric therapy a single oral dose of gatifloxacin (400mg) would be clinically equivalent to ciprofloxacin (500 mg) twice daily-in agreement with the results of a clinical study in complicated UTI performed previously [Int. J. Antimicrob. Agents (2004)].

Gatifloxacin 200 mg or 400 mg once daily is as effective as ciprofloxacin 500 mg twice daily for the treatment of patients with acute pyelonephritis or complicated urinary tract infections

The efficacy and safety of two oral dosing regimens of gatifloxacin were compared to ciprofloxacin in the treatment of complicated urinary tract infection in a randomised, double-blind multi-centre trial. One thousand one hundred and twenty-three adult patients with complicated urinary tract infection (70%) or pyelonephritis (30%) were initially enrolled, 1122 were treated. Of these, 824 were included in a modified ITT population: gatifloxacin 200 mg (274 patients) or 400 mg (280 patients) once daily or ciprofloxacin 500 mg twice daily for 5-14 days (269 patients). Bacteriological and clinical responses were assessed 7-9 days after the end of treatment (EOT) and 4-6 weeks post-treatment (end of study visit, EOS). The bacteriological response rates per patient at EOT in the gatifloxacin 400 mg, gatifloxacin 200 mg and ciprofloxacin groups were 77% (207/269), 78% (208/268) and 73% (190/259), respectively. At EOS they were slightly lower: 70% (184/262), 71% (176/248) and 69% (174/252), respectively. The clinical responses at EOT were 69% (190/277), 70% (190/273) and 65% (174/266). At EOS they were 71% (193/273), 70% (182/259) and 74% (190/258). The overall eradication rates of initial pathogens at EOT and EOS were 85.3% and 88.4% in the gatifloxacin 400 mg group; 84.1 and 90.1% in the gatifloxacin 200 mg group and 85.1 and 91.4% in the ciprofloxacin group. Both oral regimens of gatifloxacin were as effective as that of ciprofloxacin. All treatment groups showed a similar safety profile, nausea being the most frequently reported adverse event.

Gatifloxacin 400mg as a single shot or 200mg once daily for 3 days is as effective as ciprofloxacin 250mg twice daily for the treatment of patients with uncomplicated urinary tract infections

The efficacy and safety of two oral dosing regimens of gatifloxacin compared with ciprofloxacin for the treatment of acute uncomplicated lower urinary tract infection was investigated in a double-blind, randomised study, in adult female patients who received either gatifloxacin (400 mg as a single shot or 3 days of 200 mg once daily) or ciprofloxacin (250 mg given twice daily for 3 days). Bacteriological and clinical responses were assessed 7-9 days after the end of treatment (EOT), and 4-6 weeks post-treatment (end of study, EOS). One thousand one hundred and two women were treated, 741 (248 in the gatifloxacin 400 mg group, 252 in the gatifloxacin 200 mg group, and 241 in the ciprofloxacin group) presented with bacteriological proof of infection and entered the efficacy analysis. The bacteriological response per patient at EOT in the three groups were 80% (177/220) [95% CI to ciprofloxacin -8.4%; 6.4%], 83% (184/222) [95% CI to ciprofloxacin -5.9%; 8.7%] and 81% (176/216), respectively. At the follow-up assessment they were slightly lower, 75% (167/224), 79% (169/213) and 79% (171/217), respectively. The clinical responses at EOT were 81% (197/243) [95% CI to ciprofloxacin -10.2%; 3.4%], 85% (213/250) [95% CI to ciprofloxacin -5.7%; 7.2%] and 85% (201/238), respectively. At EOS they were 82% (195/239), 88% (212/241) and 86% (200/233), respectively. The eradication rates for all initial pathogens at the EOT were 90.3% in the gatifloxacin 400 mg S.D. group, 90.6% in the gatifloxacin 200 mg group, and 88.3% in the ciprofloxacin group. All treatment groups showed a similar safety profile. The incidence of treatment-related adverse events was comparable, the majority of adverse events were of mild or moderate intensity and the medications were well tolerated. Both the administration of gatifloxacin 200 mg once daily for 3 days, and gatifloxacin 400 mg as a single shot were shown to be equivalent to ciprofloxacin 250 mg twice daily for 3 days for the treatment of acute uncomplicated lower urinary tract infections.

Bacteriologic and clinical efficacy of oral gatifloxacin for the treatment of recurrent/nonresponsive acute otitis media: an open label, noncomparative, double tympanocentesis study

BACKGROUND

Gatifloxacin is an 8-methoxyfluoroquinolone with good activity against respiratory pathogens.

OBJECTIVES

To document the bacteriologic and clinical efficacy of gatifloxacin in recurrent/nonresponsive acute otitis media (AOM).

METHODS

One hundred sixty patients 6 to 48 months of age with recurrent/nonresponsive AOM received gatifloxacin suspension (10 mg/kg once daily for 10 days). Recurrent AOM was defined as > or =3 AOM episodes during the previous 6 months or > or =4 AOM episodes during the previous 12 months. Nonresponsive AOM was defined as AOM occurring < or =14 days after completing antibiotic treatment or not improving after > or =48 h of therapy. Middle ear fluid (MEF) obtained by tympanocentesis pretreatment (Day 1) and 3 to 5 days after initiation of treatment (Days 4 to 6) was cultured. Additional MEF cultures were obtained if clinical failure or recurrence of AOM occurred. Bacteriologic failure was defined by culture-positive MEF during treatment. Patients were followed until Days 22 to 28. Susceptibility was determined by broth microdilution.

RESULTS

One hundred twenty-eight (80%) patients completed treatment, and 32 discontinued the study prematurely (adverse events, 17; lost to follow-up, 10; consent withdrawal, 3; and laboratory abnormalities, 2). From 89 patients (median age, 1 year; median number of prior AOM episodes, 4; range, 0 to 12), 121 pathogens were recovered: Haemophilus influenzae, 74 (61%); Streptococcus pneumoniae, 36 (30%); Moraxella catarrhalis, 9 (7%); and Streptococcus pyogenes, 2 (2%). The 36 S. pneumoniae isolates were susceptible to gatifloxacin (MIC50 0.25 microg/ml); 26 of 36 (72%) were penicillin-nonsusceptible (15 fully resistant). All 74 H. influenzae isolates were susceptible to gatifloxacin (MIC < or = 0.03 mg/ml). Fourteen of 74 (19%) and 9 of 9 (100%) H. influenzae and M. catarrhalis isolates, respectively, produced beta-lactamase. Bacteriologic eradication was achieved for 118 of 121 (98%) pathogens: 74 of 74 H. influenzae; 34 of 36 (94%) S. pneumoniae; 9 of 9 M. catarrhalis; and 1 of 2 S. pyogenes. Clinical improvement/cure at end of treatment was seen in 103 of 114 (90%) clinically evaluable patients. Clinical recurrence of AOM after completion of therapy occurred in 31 patients. Of the 27 recurrent AOM cases in which tympanocentesis was performed, there were 16 (59%) new infections, 4 (15%) culture-negative results and only 7 (26%) true bacteriologic relapses. Adverse events were recorded in 21 of 160 (13%) patients: vomiting, 16; diarrhea, 3; maculopapular rash, 2. No articular adverse events were recorded.

CONCLUSION

Gatifloxacin is efficacious and safe for the treatment of recurrent/nonresponsive AOM.

Global patterns of susceptibility for 21 commonly utilized antimicrobial agents tested against 48,440 Enterobacteriaceae in the SENTRY Antimicrobial Surveillance Program (1997-2001)

A total of 48,440 Enterobacteriaceae isolates collected consecutively from patients hospitalized in participant SENTRY Antimicrobial Surveillance Program sites in four international regions (Asia-Pacific, Europe, Latin America, and North America) were tested by reference broth microdilution method against the most commonly used antimicrobial agents. The most active compounds could be divided in 3 groups based on their spectrum of activity. The first group included meropenem and imipenem, with 99.9% susceptibilty (S) rates for the Enterobacteriaceae. The second group includes amikacin (97.3% S) and cefepime (97.2% S); and a third active group had a rank order of susceptibility of: gatifloxacin = levofloxacin (91.7% S) > ceftazidime (91.4% S) > ceftriaxone (91.2% S) > aztreonam (91.1% S) > gentamicin (90.6% S) > piperacillin/tazobactam = ciprofloxacin (90.5% susceptibility). These latter antimicrobial agents presented susceptibility rates of approximately 90% (89.8%-91.7%). Continued resistance surveillance by various programs remain necessary to monitor the in vitro effectiveness of antimicrobial agents currently used in clinical practice.

Treatment of bacterial skin and skin structure infections

Bacterial skin and skin structure infections (SSSIs) are among the most frequently seen infectious entities in the community setting and occasionally in the institutional setting. A wide variety of SSSIs exist, with cellulitis, impetigo and folliculitis being the most common. Most SSSIs are caused by aerobic staphylococci and streptococci, with aerobic Gram-negative bacilli and anaerobes being involved in more complicated infections. Systemic therapy with a variety of beta-lactams, macrolides and lincosamides (clindamycin) have been the cornerstone of SSSI therapy for many years. With the exception of mupirocin, topical therapy occupies a small therapeutic niche. Despite the emergence of antimicrobial resistance among the pathogens most commonly associated with SSSIs (for example, Streptococcus pyogenes and macrolides; Staphylococcus aureus and methicillin, vancomycin, penicillin and mupirocin), few treatment failures have been reported. The newest antimicrobials reviewed herein (linezolid, quinupristin/dalfopristin, gatifloxacin, gemifloxacin and moxifloxacin) are not a significant improvement upon older agents in the treatment of SSSIs. Perhaps this assessment will change if the penetrance of the antimicrobial resistance patterns described above reach a critical threshold and clinical failures become more widespread.

Fluoroquinolones in the elderly: safety considerations

Fluoroquinolones such as ciprofloxacin, levofloxacin, moxifloxacin and gatifloxacin are widely used for the treatment of bacterial infections. Fluoroquinolone-induced adverse effects have not been reported to occur with increased frequency in the elderly, but large trials comparing the tolerability in aged and young individuals are not available. Renal function declines consistently with age and recommendations for dosage changes of renally eliminated fluoroquinolones (ofloxacin, levofloxacin, gatifloxacin) are related to changes in kidney function rather than to age per se. However, during routine clinical work, creatinine clearance data are usually not available; thus it seems more practical to recommend dosage adjustment for elderly individuals in whom low creatinine clearance values can be expected. Reactions of the gastrointestinal tract are the most often observed adverse effects during therapy with fluoroquinolones; however, compared with many other antibacterials, fluoroquinolones are less frequently associated with diarrhoea. Similarly, hypersensitivity reactions, as observed during therapy with penicillins and other beta-lactam agents, occur more rarely during fluoroquinolone therapy. Adverse reactions of the CNS are of particular concern for the elderly population. Elderly patients with impairments of the CNS (e.g. epilepsy, pronounced arteriosclerosis) should be treated with fluoroquinolones only under close supervision. Probably, 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. Fluoroquinolones can cause QT interval prolongation. Therefore, 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. Chondrotoxicity of fluoroquinolones, as observed in immature animals, has led to restricted use in paediatric patients, but there is no indication that similar effects could occur in joint cartilage of adults. Tendinitis and tendon ruptures have occurred in rare cases as late as several months after treatment with some fluoroquinolones. Chronic renal diseases, concomitant use of corticosteroids and age over 60 years have been recognised as risk factors for fluoroquinolone-induced tendon disorders. Overall, the widely used fluoroquinolones discussed in this review are generally well tolerated. Nevertheless, as with all drugs, their specific adverse effect profiles must be considered when they are chosen for treatment of bacterial infections. Because of physiological changes in renal function and in case of certain comorbidities, some special considerations are necessary when fluoroquinolones are used to treat elderly patients.

Randomized, open-label, parallel-group, multicenter study of the efficacy and tolerability of IV gatifloxacin with the option for oral stepdown gatifloxacin versus IV ceftriaxone (with or without erythromycin or clarithromycin) with the option for oral stepdown clarithromycin for treatment of patients with mild to moderate community-acquired pneumonia requiring hospitalization

BACKGROUND

Empiric therapy for community-acquired pneumonia (CAP) requires the use of antibiotics with activity against a broad spectrum of respiratory pathogens and suitable pharmacokinetic properties to simplify IV-to-oral step-down therapy switches.

OBJECTIVE

The aim of this study was to compare the efficacy and tolerability of IV gatifloxacin with the option for oral stepdown gatifloxacin with a standard regimen of IV ceftriaxone (with or without erythromycin or clarithromycin) with the option for oral stepdown clarithromycin in patients with mild to moderate CAP requiring hospitalization.

METHODS

In a randomized, open-label, parallel-group, multicenter study, adults with CAP received 7 to 14 days of treatment with either IV gatifloxacin 400 mg QD with the stepdown option or IV ceftriaxone 1 or 2 g QD (with or without erythromycin 0.5 or 1 g QID or clarithromycin 500 mg BID) with the stepdown option.

RESULTS

One hundred seventy adults with CAP were included in the study. IV gatifloxacin was stepped down to oral gatifloxacin in 90.6% (7785) of patients; IV ceftriaxone was stepped down to oral clarithromycin in 87.1% (7485) of patients. Among clinically evaluable patients (n = 153), cure rates at 1 to 3 days after treatment were 97.4% in the gatifloxacin group (7476) and 90.9% in the ceftriaxone group (7077), with a 95% CI for the difference (-3.7% to 19.1%) indicating statistical equivalence. In patients in whom pathogens were isolated from pretreatment sputum cultures, bacteriologic eradication rates were 100.0% (2929) and 90.9% (3033), respectively. Both regimens were well tolerated; treatment-related adverse events occurred in 27.1% (2385) and 21.2% (1885) of patients, respectively.

CONCLUSIONS

In the population studied, treatment with IV gatifloxacin with an option for oral stepdown gatifloxacin was as effective for achieving clinical cure as IV ceftriaxone (with or without concomitant IV erythromycin or clarithromycin) with an option for oral stepdown clarithromycin. Both regimens were well tolerated.

Controlling acute bacterial maxillary sinusitis

In acute maxillary sinusitis, after an initial viral episode, bacterial infection can be demonstrated using specific investigations and bacterial isolation. In the vast majority of cases, however, the diagnosis is presumptive. Symptomatic treatments tend to reduce pain and inflammation for easier pus drainage. The decision for or against antibiotic therapy continues to be a matter of debate. Many antibiotics have been used but modern guidelines have established recommendations for the choice and duration of treatments, based on (i) knowledge of pathogens and of their resistance profiles; (ii) improved understanding of the pharmacology of antibiotics, guiding doses and administration routes; (iii) comparative double-blind studies, evaluating antibiotics versus placebo and beta-lactams versus macrolides. Use of newer drugs (fluoroquinolones, ketolides) must be discussed in terms of cost and efficacy.