STUDY OBJECTIVE: To determine the effect of St. John's wort on the pharmacokinetics of imatinib mesylate. DESIGN: Open-label, complete crossover, fixed-sequence, pharmacokinetic study. SETTING: Clinical research center. SUBJECTS: Ten healthy adult volunteers. INTERVENTION: Single 400-mg oral doses of imatinib were administered before and after 2 weeks of treatment with St. John's wort 300 mg 3 times/day. MEASUREMENTS AND MAIN RESULTS: The pharmacokinetics of imatinib were significantly altered by St. John's wort, with reductions of 32% in the median area under the concentration-time curve from time zero to infinity (p=0.0001), 29% in maximum observed concentration (p=0.005), and 21% in half-life (p=0.0001). Protein binding ranged from 97.7-90.3% (mean 94.9%), was concentration independent, and was not altered by St. John's wort. Therapeutic outcomes of imatinib have been shown to correlate with both dose and drug concentrations. CONCLUSION: Coadministration of imatinib with St. John's wort may compromise imatinib's clinical efficacy.
STUDY OBJECTIVE: To determine the effect of St. John's wort on the pharmacokinetics of imatinib mesylate. DESIGN: Open-label, complete crossover, fixed-sequence, pharmacokinetic study. SETTING: Clinical research center. SUBJECTS: Ten healthy adult volunteers. INTERVENTION: Single 400-mg oral doses of imatinib were administered before and after 2 weeks of treatment with St. John's wort 300 mg 3 times/day. MEASUREMENTS AND MAIN RESULTS: The pharmacokinetics of imatinib were significantly altered by St. John's wort, with reductions of 32% in the median area under the concentration-time curve from time zero to infinity (p=0.0001), 29% in maximum observed concentration (p=0.005), and 21% in half-life (p=0.0001). Protein binding ranged from 97.7-90.3% (mean 94.9%), was concentration independent, and was not altered by St. John's wort. Therapeutic outcomes of imatinib have been shown to correlate with both dose and drug concentrations. CONCLUSION: Coadministration of imatinib with St. John's wort may compromise imatinib's clinical efficacy.
Authors: Jan H Beumer; Venkateswaran C Pillai; Robert A Parise; Susan M Christner; Brian F Kiesel; Michelle A Rudek; Raman Venkataramanan Journal: Br J Clin Pharmacol Date: 2015-09-19 Impact factor: 4.335