Personalized therapeutics for levofloxacin: a focus on pharmacokinetic concerns

Optimization Strategies Aimed to Increase the Efficacy of Helicobacter pylori Eradication Therapies with Quinolones

H. pylori infection is the main cause of gastritis, gastroduodenal ulcer disease, and gastric cancer. Fluoroquinolones such as levofloxacin, or more recently moxifloxacin or sitafloxacin, are efficacious alternatives to standard antibiotics for H. pylori eradication. The aim of the present review is to summarize the role of quinolone-based eradication therapies, mainly focusing on the optimization strategies aimed to increase their efficacy. Several meta-analyses have shown that, after failure of a first-line eradication treatment, a levofloxacin-containing rescue regimen is at least equally effective, and better tolerated, than the generally recommended bismuth quadruple regimen. Compliance with the levofloxacin regimens is excellent, and the safety profile is favourable. Higher cure rates have been reported with longer treatments (>10-14 days), and 500 mg levofloxacin daily is the recommended dose. Adding bismuth to the standard triple regimen (PPI-amoxicillin-levofloxacin) has been associated with encouraging results. Unfortunately, resistance to quinolones is easily acquired and is increasing in most countries, being associated with a decrease in the eradication rate of H. pylori. In summary, a quinolone (mainly levofloxacin)-containing regimen is an encouraging second-line (or even third-line) strategy, and a safe and simple alternative to bismuth quadruple therapy in patients whose previous H. pylori eradication therapy has failed.

Revisiting Oral Fluoroquinolone and Multivalent Cation Drug-Drug Interactions: Are They Still Relevant?

Fluoroquinolones are a widely-prescribed, broad-spectrum class of antibiotics with several oral formulations notable for their high bioavailability. For certain infections, fluoroquinolones are the first line or only treatment choice. When administered orally, fluoroquinolones require proper administration to ensure adequate systemic absorption and, thereby, protect patients from treatment failure. Oral drug preparations that contain multivalent cations are well known to chelate with fluoroquinolones in the gastrointestinal tract; co-administration may lead to clinically significant decreases in oral fluoroquinolone bioavailability and an overall increase in fluoroquinolone-resistant bacteria. Based on a search and evaluation of the literature, this focused review describes oral fluoroquinolone-multivalent cation drug-drug interactions and their magnitude and offers several clinical management strategies for these potentially clinically significant interactions.