title: Drug Interactions with Angiotensin Receptor Blockers: Role of Human Cytochromes P450.
abstract: BACKGROUND
  Angiotensin receptor blockers (ARBs) are the most recent class of agents for the treatment of hypertension. However, ARBs may cause a low incidence of headache, upper respiratory infection, back pain, muscle cramps, fatigue, dizziness, and many other side effects. In some cases, such toxicity is associated with pharmacokinetic alterations.
  
  
  METHODS
  The cytochrome P450 (CYP) enzyme system plays an important role in a lot of clinically important pharmacokinetic drug interactions. To identify relevant studies on drug-drug and food-drug pharmacokinetic interactions with the ARBs, a literature search of Google Scholar was performed from January 1994 to June 2015, with the following keywords: 'losartan', 'valsartan,' 'candesartan,' 'irbesartan,' 'telmisartan,' 'eprosartan,' 'olmesartan,' and 'azilsartan', combined with the keyword 'pharmacokinetic interactions' and 'CYP'.
  
  
  RESULTS
  Based on the literatures published, it has been demonstrated that pharmacokinetic interactions of losartan with other agents are mainly via CYP2C9- and CYP3A4-mediated, the role played by CYP enzyme system in the metabolism of valsartan, candesartan, irbesartan, and azilsartan appears modest, and cytochrome P450 system has no influence on the metabolism of telmisartan, eprosartan, olmesartan. Therefore, according to these pharmacokinetic findings, no dosage adjustment is recommended when eprosartan, telmisartan and olmesartan are combined with other pharmacological agents in patients with hypertension.
  
  
  CONCLUSIONS
  This review summarize the available data on cytochrome P450 - related drug-drug interactions reported in the literature for the eight ARBs. Knowledge of the pharmacokinetic properties of the ARBs should allow the avoidance of the majority of drug interactions without compromising therapeutic benefits.
authors.forename: Ruirui
authors.initials: R
authors.lastname: Yang
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Luo
authors.affiliation: School of Chinese Materia Medica, Beijing University of Chinese Medicine, No. 6, Zhonghuan South Road, Wangjing, Chaoyang District, Beijing 100102, P.R. China. liuyang@bucm.edu.cn.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Mohan
authors.initials: M
authors.lastname: Sun
authors.forename: Ling
authors.initials: L
authors.lastname: Zheng
authors.forename: Yingying
authors.initials: Y
authors.lastname: Chen
authors.forename: Yanping
authors.initials: Y
authors.lastname: Li
authors.forename: Hao
authors.initials: H
authors.lastname: Wang
authors.forename: Lingzhu
authors.initials: L
authors.lastname: Chen
authors.forename: Ming
authors.initials: M
authors.lastname: Wu
authors.affiliation: Science and Technology Department, Beijing University of Chinese Medicine, No. 11, North Third Ring Road, Chaoyang District, Beijing 100029, P.R. China. hh686@126.com.
authors.forename: Huihui
authors.initials: H
authors.lastname: Zhao
mesh_terms: D057911:Angiotensin Receptor Antagonists / Q000493:pharmacokinetics*; D000818:Animals; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D004347:Drug Interactions; D006801:Humans
chemical_list: D057911:Angiotensin Receptor Antagonists; D003577:Cytochrome P-450 Enzyme System