Comparative plasma pharmacokinetics of theophylline and ethylenediamine after the administration of aminophylline to man

Author:

Cotgreave Ian A1,Caldwell John1

Affiliation:

1. Department of Pharmacology, St Mary’s Hospital Medical School, London W2 1PG, U.K.

Abstract

Abstract Plasma concentrations of theophylline and ethylenediamine have been examined after the oral and intravenous administration of aminophylline to three healthy male volunteers who received on separate occasions 250 mg aminophylline i.v. or 300 mg aminophylline by mouth. Blood samples were taken at regular intervals and the plasma levels of theophylline and ethylenediamine were assayed by h.p.l.c. After i.v. injection, plasma concentrations of theophylline were described by a two-compartment open model, with t1/2α 6 min, Vc 191 ml kg−1, t1/2β 6·0 h and Vp 217 ml kg−1. The plasma concentrations of ethylenediamine also exhibited a biphasic decline, the parameters of the two-compartment open model being t1/2α 7 min, Vc 214 ml kg−1, t1/2β 32 min and Vp 133 ml kg−1 (all values given are means of three subjects). The ratio of theophylline/ethylenediamine in plasma rose rapidly from the initial value of 6·2 (the ratio of the two compounds in aminophylline) over the first 10 min post injection to 47 at 120 min. After this time, ethylenediamine was not measurable in plasma, although theophylline was present for at least 6 h after dosing. Upon oral administration of aminophylline, plasma concentrations of theophylline rose to a peak value of 7·4 μg ml−1 at 1 h, falling thereafter with a t1/2 of 8·0 h. Ethylenediamine, by contrast, could only be detected over the first 2 h after dosing, in amounts below 0·4 μg ml−1. Comparison of oral and i.v. data showed the bioavailability of ethylenediamine was approximately 34% in comparison with a value of 88% for theophylline. These data indicate that the two components of aminophylline are handled independently by the body and that there is no molecular association between theophylline and ethylenediamine in biological media.

Publisher

Oxford University Press (OUP)

Subject

Pharmaceutical Science,Pharmacology

Cited by 15 articles. 订阅此论文施引文献 订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3