Quantitative assessment of the hepatic pharmacokinetics of the antimicrobial sitafloxacin in humans using in vivo19F magnetic resonance spectroscopy

Quantitative assessment of the hepatic pharmacokinetics of the antimicrobial sitafloxacin in humans using in vivo F-19 magnetic resonance spectroscopy Aims To measure hepatic concentrations of the fluorine-containing antimicrobial, sitafloxacin, using in vivo(19)F magnetic resonance spectroscopy (MRS). Methods Data were acquired from eight healthy subjects at 2, 5, 8 and 24 h following doses of 500 mg day(-1) for 5 days using a H-1/F-19 surface coil in a 1.5T clinical MR system. Tissue water was used as a reference. Results Estimated liver concentrations at 2 h were 15.0 +/- 4.0 mug ml(-1) (mean +/- 95% CI), compared with 3.54 +/- 0.58 mug ml(-1) in plasma (n = 6), and fell below threshold concentrations (2 mug ml(-1)) by 24 h. Conclusions F-19 MRS is able to detect and quantify sitafloxacin in the liver. There was no evidence for the hepatic retention of the drug.