The effect of sucralfate pretreatment on the pharmacokinetics of ciprofloxacin.

Based on the results of our study of norfloxacin-sucralfate coadministration, we suspected that sucralfate would interact also with ciprofloxacin if the drugs were administered concurrently. Therefore, we decided to give a 1-g dose of sucralfate at 6 and 2 hours before a single 750-mg dose of ciprofloxacin and evaluate its effect on the bioavailability of ciprofloxacin. Twelve healthy, male volunteers received ciprofloxacin alone and with sucralfate pretreatment in a randomized, balanced, crossover design. Blood and urine samples were collected over 24 hours after ciprofloxacin administration, and drug concentrations were assayed by high-performance liquid chromatography. When sucralfate was given at 6 and 2 hours before ciprofloxacin, an average 30% decrease in ciprofloxacin's bioavailability was noted (p less than 0.05). Four of the 12 subjects, however, had decreases in the agent's area under the curve of more than 50% with sucralfate pretreatment. The results of this study suggest that ciprofloxacin and sucralfate should not be administered concurrently until a dosing interval is found that will avoid this potential interaction.