Levofloxacin. Tuberculosis (Edinb). 2008;88:119-121. [PMID: 18486047 DOI: 10.1016/s1472-9792(08)70013-1]

Preclinical safety evaluation of levonadifloxacin, a novel anti-methicillin-resistant Staphyloccocus aureus benzoquinolizine fluoroquinolone by intravenous and oral administration

Fluoroquinolone (FQ) antibacterials have drawn heightened attention from various international regulatory agencies due to their class-specific side effects. Levonadifloxacin is a novel broad spectrum benzoquinolizine FQ active against methicillin-resistant Staphyloccocus aureus (MRSA). Owing to FQ-associated safety concerns, extensive preclinical safety pharmacology (central nervous system and cardiac safety) and toxicology studies (subacute repeat-dose toxicity, genotoxicity, phototoxicity and chondrotoxicity) of levonadifloxacin were performed at relatively high doses. Intravenous (IV) and oral studies were conducted using WCK 771 (l-arginine salt of levonadifloxacin) and WCK 2349 (l-alanine ester prodrug of levonadifloxacin), respectively. Safety pharmacology studies following single dose revealed no adverse effects on central nervous system (including seizure) in mice and cardiovascular system (hERG and monkey telemetry). In repeat-dose toxicity studies, except for IV bolus dosing related effects in rat (hyperactivity, mild convulsion, polypnoea and injection site irritation) and dog (emesis and salivation), no other adverse findings limiting the dosing duration were observed. No major biochemical, haematological, gross or histopathological changes suggestive of damage to vital organs were observed in either WCK 771- or WCK 2349-treated groups. WCK 771 and WCK 2349 were found to be nongenotoxic; however, they showed weak phototoxicity that was comparable with levofloxacin. WCK 771 showed chondrotoxicity in the Beagle dog pups on repeat-dose administration; however, the severity level was lower than ofloxacin. Overall, preclinical safety studies helped establish wider safety margin for WCK 771 and WCK 2349 that supports administration of higher therapeutic doses in humans by both IV and oral routes, thereby enabling safe anti-MRSA treatment.

Approaches for setting occupational exposure limits in the pharmaceutical industry

The use of pharmaceutical drugs has provided a cure for many diseases. However, unintended exposure to drugs in the manufacturing workplace can cause significant health hazards to workers. It is important to protect the workforce from these deleterious effects by limiting exposure to an acceptable level, the occupational exposure limit (OEL). OEL is defined as airborne concentrations (expressed as a time-weighted average for a conventional 8-h workday and a 40-h work week) of a substance to which nearly all workers may be repeatedly exposed (for a working lifetime) without adverse effects. Determination of OELs has become very challenging over time, requiring an overall assessment of the preclinical and clinical data of the drug being manufactured. Previously, to derive OEL values, toxicologists used animal no-observed-adverse-effect level (NOAEL) data, which have been replaced with the overall assessment of animal and human data, placing a higher emphasis on human health-based data. A major advantage of working with human pharmaceuticals is that sufficient clinical data are available for them in most cases. The present manuscript reviews the latest knowledge regarding the derivation of occupational exposure limits as health-based exposure limits (HBELs) for pharmaceuticals. We have provided examples of OEL calculations for various drugs including levofloxacin (CAS No. 100986-85-4), dienogest (CAS no. 65928-58-7), and acetylsalicylic acid (ASA, CAS no. 50-78-2) using human data. This report will benefit professionals in the OEL domain in understanding this highly important, growing, and challenging field.

Determination of levofloxacin by HPLC with fluorescence detection in human breast milk

Aim: A new HPLC method with fluorescence detection has been developed and validated for the determination of levofloxacin, one of the fluoroquinolone class antibiotics, in breast milk. Materials & methods: Chromatographic separation was carried out on a reversed phase C18 column with acetonitrile and 10 mM o-phosphoric acid (25:75, v/v) mobile phase composition. Moxifloxacin was used as internal standard and the peaks were detected by fluorescence detection. Results & conclusion: Calibration graph was found linearly within the range of 2.5-500 ng/ml. Limit of detection and limit of quantification were found to be 0.63 and 2.11 ng/ml, respectively. Mean absolute recovery was 96.18%. The developed method has been successfully applied to the determination of levofloxacin in human breast milk taken from two healthy volunteers.

Prevention and treatment of tuberculosis in solid organ transplant recipients

Introduction: Tuberculosis (TB) in solid organ transplant (SOT) recipients is associated with significant morbidity and mortality. Its management in transplant recipients is difficult and highly complex, given the underlying immunosuppression and the risks of drug-drug interactions imposed by immunosuppressive drugs that are needed to maintain the transplant allograft.Areas covered: We provide a brief review of TB in SOT and discuss the clinical indications, mechanisms of action and drug resistance, drug-drug interactions, and adverse effects of anti-TB drugs. We provide a summary of recent clinical trials, which serve as the foundation for current recommendations. We further include relevant updates on new agents being evaluated for clinical use in TB management.Expert commentary: TB causes significant morbidity in SOT recipients. The drugs used in the treatment for latent TB and active disease in SOT are similar to the regimens used in the general population. However, TB disease in transplant recipients is more difficult to manage because of the potential for hepatotoxicity and the complex drug-drug interactions with immunosuppressive drugs. We believe that alternative regimens suited for the vulnerable transplant population, and more therapeutic drug options are needed given the adverse toxicities associated with currently approved anti-TB drugs.

Levofloxacin/amoxicillin-based schemes vs quadruple therapy for Helicobacter pylori eradication in second-line

Worldwide prevalence of Helicobacter pylori (H. pylori) infection is approximately 50%, with the highest being in developing countries. We compared cure rates and tolerability (SE) of second-line anti-H. pylori levofloxacin/amoxicillin (LA)-based triple regimens vs standard quadruple therapy (QT). An English language literature search was performed up to October 2010. A meta-analysis was performed including randomized clinical trials comparing 7- or 10-d LA with 7-d QT. In total, 10 articles and four abstracts were identified. Overall eradication rate in LA was 76.5% (95% CI: 64.4%-97.6%). When only 7-d regimens were included, cure rate was 70.6% (95% CI: 40.2%-99.1%), whereas for 10-d combinations, cure rate was significantly higher (88.7%; 95% CI: 56.1%-109.9%; P < 0.05). Main eradication rate for QT was 67.4% (95% CI: 49.7%-67.9%). The 7-d LA and QT showed comparable efficacy [odds ratio (OR): 1.09; 95% CI: 0.63-1.87], whereas the 10-d LA regimen was significantly more effective than QT (OR: 5.05; 95% CI: 2.74-9.31; P < 0.001; I² = 75%). No differences were reported in QT eradication rates among Asian and European studies, whereas LA regimens were more effective in European populations (78.3% vs 67.7%; P = 0.05). Incidence of SE was lower in LA therapy than QT (OR: 0.39; 95% CI: 0.18-0.85; P = 0.02). A higher rate of side effects was reported in Asian patients who received QT. Our findings support the use of 10-d LA as a simple second-line treatment for H. pylori eradication with an excellent eradication rate and tolerability. The optimal second-line alternative scheme might differ among countries depending on quinolone resistance.