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Effect of danshen extract on pharmacokinetics of theophylline in healthy volunteers
Author(s) -
Qiu Furong,
Wang Guangji,
Zhao Yanan,
Sun Hua,
Mao Guoguang,
A Jiyi,
Sun Jian
Publication year - 2008
Publication title -
british journal of clinical pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.216
H-Index - 146
eISSN - 1365-2125
pISSN - 0306-5251
DOI - 10.1111/j.1365-2125.2007.03027.x
Subject(s) - theophylline , pharmacokinetics , pharmacology , medicine , cyp1a2 , therapeutic index , bronchodilator , traditional medicine , asthma , traditional chinese medicine , drug , alternative medicine , cytochrome p450 , pathology , metabolism
What is already known about this subject • Danshen extract is widely used for the treatment and prevention of coronary heart disease and other diseases of senility in Asia. • Danshen extract and theophylline may be prescribed together to treat patients with asthma. • In human, theophylline with low therapeutic index is mainly metabolized by CYP1A2. • In vitro findings have shown that human CYP1A2 is inhibited by the ethyl acetate extract of danshen and danshen pharmaceutical product. • There may be drug interactions between danshen extract and theophylline (CYP1A2 substrate). What this study adds • This study concerned drug interactions between danshen extract and theophylline in Chinese volunteers. • Long‐term oral intake of danshen extract does not change the basic pharmacokinetic parameters of theophylline. • Dose adjustment of theophylline thus may not be necessary in patients receiving concomitant therapy with danshen extract. Aims To examine the potential effect of danshen extract on the pharmacokinetics of theophylline. Methods In a sequential cross‐over study with two phases, 12 volunteers took 100 mg theophylline on day 1 and day 15. From day 2 to day 15, volunteers received danshen extract tablets three times daily, four tablets each time for 14 days. On day 15, they received four danshen extract tablets with 100 mg theophylline. Plasma concentrations of theophylline were measured on days 1 and 15 periodically for 24 h. Results The 90% confidence interval of C max , t 1/2 and CL/ F of theophylline with 14‐day danshen extract tablets vs . without comedication were (101.42, 121.36) (84.57, 106.72) and (88.82, 105.72), respectively. The time to peak plasma theophylline concentration was unchanged by danshen (P > 0.05). The pharmacokinetics parameter of theophylline was unaffected by danshen extract. Conclusions Danshen extract does not influence the metabolism of theophylline in healthy volunteers. Dose adjustment of theophylline thus may not be necessary in patients receiving concurrent therapy with danshen extract tablets.