Pharmacokinetic drug interaction and safety after coadministration of clarithromycin, amoxicillin, and ilaprazole: a randomised, open-label, one-way crossover, two parallel sequences study

PURPOSE: Ilaprazole, the latest proton pump inhibitor, can be used with clarithromycin and amoxicillin as a triple therapy regimen for eradicating Helicobacter pylori. The aim of this study was to evaluate pharmacokinetic drug interactions and safety profiles after coadministration of clarithromycin, amoxicillin, and ilaprazole. METHODS: A randomised, open-label, one-way crossover, two parallel sequences study was conducted in 32 healthy subjects. In part 1, the subjects received a single dose of ilaprazole 10 mg in period 1 and clarithromycin 500 mg and amoxicillin 1000 mg twice daily for 6 days in period 2. In part 2, the subjects received clarithromycin 500 mg and amoxicillin 1000 mg once in period 1 and ilaprazole 10 mg twice daily for 6 days in period 2. In both sequences, the three drugs were coadministrated once on day 5 in period 2. Pharmacokinetic evaluations of ilaprazole (part 1), and clarithromycin and amoxicillin (part 2) were conducted. RESULTS: Twenty-eight subjects completed the study. For ilaprazole, the peak concentration (C(max)) slightly decreased from 479 (ilaprazole alone) to 446 ng/mL (triple therapy) [Geometric least square mean ratio (90% confidence interval), 0.93 (0.70–1.22)]. The area under the concentration-time curve from 0 h to the last measurable concentration (AUC(last)) slightly increased from 3301 to 3538 μg·h/mL [1.07 (0.85–1.35)]. For clarithromycin, the C(max) slightly decreased from 1.87 to 1.72 μg/mL [0.90 (0.70–1.15)], and AUC(last) slightly increased from 14.6 to 16.5 μg·h/mL [1.09 (0.87–1.37)]. For amoxicillin, the C(max) slightly decreased from 9.37 to 8.14 μg/mL [0.86 (0.74–1.01)], and AUC(last) slightly decreased from 27.9 to 26.7 μg·h/mL [0.98 (0.83–1.16)]. These changes in the PK parameters of each drug were not statistically significant. CONCLUSIONS: The coadministration of ilaprazole, clarithromycin, and amoxicillin was tolerable and did not cause a significant PK drug interaction. Thus, a triple therapy regimen comprising ilaprazole, clarithromycin, and amoxicillin may be an option for the eradication of H. pylori. Clinicaltrials.gov number: NCT02998437. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s00228-018-2489-2) contains supplementary material, which is available to authorized users.