Assessment of the effects of ciprofloxacin and nalidixic acid on cerebral blood flow and metabolism in healthy subjects by positron emission tomography.

ABSTRACT

STUDY OBJECTIVES: The mechanism by which the fluorinated quinolones produce central nervous system effects is unknown. Using positron emission tomography (PET), we evaluated the effects of two quinolones on brain blood flow as well as on oxygen and glucose metabolism. These determinations were done in conjunction with ophthalmologic and neuro-ophthalmologic testing. DESIGN: Randomized, double-blind, placebo-controlled, 7-day course of ciprofloxacin 750 mg (C750) or 500 mg (C500) every 12 hours, or nalidixic acid (NA) 1 g every 6 hours. POPULATION Twenty-four healthy male volunteers, six in each treatment arm. RESULTS: [table see text] CONCLUSIONS: Compared with baseline values, NA significantly reduced brain glucose uptake, whereas C500, C750, and placebo produced no detectable effect. No compound significantly altered brain blood flow or oxygen metabolism compared with baseline or other treatments. No significant effect on electroretinographic, electro-oculographic, or other neuro-ophthalmologic tests was observed.