Levofloxacin, a fluoroquinolone and L-isomer of the racemate ofloxacin, has been approved for the treatment of acute and chronic bacterial infections. Gastrointestinal complaints are the most frequently reported adverse drug reactions to fluoroquinolones. Other adverse events include headache, dizziness, increased liver enzyme levels, photosensitivity, tachycardia, QT prolongation, and eruptions. Anaphylaxis has been documented as a rare adverse drug reaction to levofloxacin; however, diagnostic tests are needed to evaluate whether these reactions are the result of levofloxacin treatment. While the results of skin tests are considered unreliable due to false-positive responses, the oral provocation test is currently considered to be the most reliable test. Tryptase, a neutral protease, is the dominant protein component of secretory granules in human mast cells, and an increased serum concentration of tryptase is a highly sensitive indicator of anaphylaxis. Herein, we report a case of levofloxacin-induced anaphylaxis in which the patient exhibited elevated serum tryptase levels and a positive oral levofloxacin challenge test result. As anaphylaxis is potentially life-threatening, the administration of fluoroquinolones to patients who have experienced a prior reaction to this type of agent should be avoided.
Anaphylaxis ; Bacterial Infections ; Diagnostic Tests, Routine ; Dizziness ; Drug Hypersensitivity ; Drug Toxicity ; Fluoroquinolones ; Headache ; Humans ; Liver ; Mast Cells ; Ofloxacin ; Secretory Vesicles ; Skin Tests ; Tachycardia ; Tryptases

Fluoroquinolone (FQ) antibiotics are an important class of synthetic antibacterial agents. These are the most extensively used drugs for treating bacterial infections in the field of both human and veterinary medicine. Herein, the antibacterial and pharmacological properties of four fluoroquinolones: lomefloxacin, norfloxacin, ciprofloxacin, and ofloxacin have been studied. The objective of this study was to analyze the antibacterial characteristics of the different fluoroquinolones. Also, the pharmacological properties of the compounds including the Lipinski rule of five, absorption, distribution, metabolism, and excretion, LD50, drug likeliness, and toxicity were evaluated. We found that among all four FQ molecules, ofloxacin showed the highest antibacterial activity through in silico assays with a strong interaction (−38.52 kJ/mol) with the antibacterial target protein (topoisomerase-II DNA gyrase enzyme). The pharmacological and pharmacokinetic analysis also showed that the compounds ciprofloxacin, ofloxacin, lomefloxacin and norfloxacin have good pharmacological properties. Notably, ofloxacin was found to possess an IGC50 (concentration needed to inhibit 50% growth) value of 0.286 μg/L against the Tetrahymena pyriformis protozoa. It also tested negative for the Ames toxicity test, showing its non-carcinogenic character.
Absorption ; Anti-Bacterial Agents ; Bacterial Infections ; Ciprofloxacin ; Computer Simulation ; DNA Gyrase ; Fluoroquinolones* ; Humans ; Lethal Dose 50 ; Metabolism ; Norfloxacin ; Ofloxacin ; Tetrahymena pyriformis ; Toxicity Tests ; Veterinary Medicine

This study was performed to assess the neurotoxic effects of methylmercury, arsanilic acid and danofloxacin by quantification of neural-specific proteins in vitro. Quantitation of the protein markers during 14 days of differentiation indicated that the mouse ESCs were completely differentiated into neural cells by Day 8. The cells were treated with non-cytotoxic concentrations of three chemicals during differentiation. Low levels of exposure to methylmercury decreased the expression of GABAA-R and Nestin during the differentiating stage, and Nestin during the differentiated stage. In contrast, GFAP, Tuj1, and MAP2 expression was affected only by relatively high doses during both stages. Arsanilic acid affected the levels of GABA(A)-R and GFAP during the differentiated stage while the changes of Nestin and Tuj1 were greater during the differentiating stage. For the neural markers (except Nestin) expressed during both stages, danofloxacin affected protein levels at lower concentrations in the differentiated stage than the differentiating stage. Acetylcholinesterase activity was inhibited by relatively low concentrations of methylmercury and arsanilic acid during the differentiating stage while this activity was inhibited only by more than 40 microM of danofloxacin in the differentiated stage. Our results provide useful information about the different toxicities of chemicals and the impact on neural development.
Acetylcholinesterase/metabolism ; Animals ; Arsanilic Acid/*toxicity ; Cell Differentiation/*drug effects ; Embryonic Stem Cells/cytology/*drug effects ; Environmental Pollutants/*toxicity ; Fluorescent Antibody Technique ; Fluoroquinolones/*toxicity ; Gene Expression Regulation/drug effects ; Methylmercury Compounds/*toxicity ; Mice ; Nerve Tissue Proteins/metabolism ; Neurons/cytology/*drug effects ; Tetrazolium Salts/metabolism ; Thiazoles/metabolism