The Effect of Phytosterols on Quality of Life in the Treatment of Benign Prostatic Hyperplasia
作者:Craig I. Coleman、John H. Hebert、Prabashni Reddy
DOI:10.1592/phco.22.16.1426.33695
日期:2002.11
Study Objective. To investigate the effect of histamine2 (H2)-receptor antagonist-induced elevation of gastric pH on oral bioavailability of a single dose of dapsone 100 mg. Design. Prospective, randomized, crossover, open-label, single-dose pharmacokinetic study. Setting. Teaching hospital. Patients. Sixteen men were enrolled in the study; data from 11 subjects were evaluable. Interventions. Participants received two treatments separated by at least 14 days. Treatment A consisted of a single dose of dapsone 100 mg. Treatment B consisted of a single dose of dapsone 100 mg plus two doses of oral nizatidine 300 mg administered 3–4 hours apart to maintain gastric pH above 6.0. Plasma samples collected before and up to 120 hours after dapsone administration were analyzed for dapsone and monoacetyldapsone (MADDS) by high-performance liquid chromatography. Pharmacokinetic parameters were determined by noncompartmental analysis. Measurements and Main Results. Gastric pH in the first 6 hours after dapsone administration was above 6.0 for a mean ± SD of 1.1% ± 2.9% of the time in the absence of nizatidine and 69.5% ± 18.0% of the time during nizatidine therapy. The geometric mean dapsone maximum plasma concentration (Cmax) declined by 13% (p<0.01), and median time to Cmaxoccurred 2 hours later (p<0.01) with nizatidine coadministration compared with dapsone alone. Inclusion of the 90% confidence interval for the mean Cmax ratio within the equivalence interval of 0.8–1.25 demonstrated the lack of clinical significance for this modest decrease in Cmax. Neither the area under the dapsone plasma concentration-time curve from zero to infinity nor the elimination half-life of dapsone were significantly altered by nizatidine. No clinically significant changes were observed in the pharmacokinetics of MADDS with regard to coadministration of nizatidine. Conclusion. Elevation of gastric pH by H2-receptor antagonists, such as nizatidine, does not result in clinically important changes in the rate or extent of oral dapsone absorption.
研究目的研究组胺2 (H2)受体拮抗剂引起的胃pH值升高对单剂100毫克达索酮口服生物利用度的影响。 设计。前瞻性、随机、交叉、开放标签、单剂量药代动力学研究。 地点: 教学医院教学医院。 患者。16 名男性参加了研究,其中 11 名受试者的数据可进行评估。 干预措施。受试者接受了两次治疗,每次治疗间隔至少 14 天。治疗 A 包括单剂量的达帕松 100 毫克。治疗 B 包括单剂量达泼松 100 毫克和两次口服尼扎替丁 300 毫克,每次间隔 3-4 小时,以维持胃液 pH 值高于 6.0。通过高效液相色谱法分析了在服用达哌酮之前和之后120小时内采集的血浆样本中的达哌酮和单乙酰达哌酮(MADDS)含量。药代动力学参数通过非室分析法确定。 测量值和主要结果。在没有使用尼扎替丁的情况下,给药后前6小时胃pH值高于6.0的平均值(± SD)为1.1% ± 2.9%,而在使用尼扎替丁的情况下,胃pH值高于6.0的平均值(± SD)为69.5% ± 18.0%。与单独使用达哌酮相比,联合使用尼扎替丁后,达哌酮的几何平均最大血浆浓度(Cmax)下降了13%(p<0.01),达到Cmax的中位时间推迟了2小时(p<0.01)。将平均Cmax比值的90%置信区间纳入0.8-1.25的等效区间,表明Cmax的适度下降缺乏临床意义。尼扎替丁对达帕酮血浆浓度-时间曲线从零到无穷大的下面积以及达帕酮的消除半衰期均无明显改变。在联合使用尼扎替丁的情况下,MADDS 的药代动力学未观察到具有临床意义的变化。 结论尼扎替丁等H2受体拮抗剂会升高胃pH值,但不会导致口服多普生的吸收率或吸收程度发生具有临床意义的变化。