title: Effect of estrogen receptor modulator tamoxifen on blood pressure, plasma renin activity, and renal sodium excretion.
abstract: BACKGROUND
  Adjuvant treatment with the estrogen receptor modulator tamoxifen is a well established long-term therapy in breast cancer. This study investigated the effect of tamoxifen on blood pressure (BP) and on factors by which it might be influenced.
  
  
  METHODS
  Normotensive postmenopausal women on > 12 months adjuvant tamoxifen therapy were randomized to withdraw or continue tamoxifen for 6 weeks and then to crossover to the alternative regimen for a second 6-week period. Measurements of clinic and ambulatory BP, plasma renin activity (PRA), and fractional sodium excretion (FE(Na)) were performed at baseline and at the end of each study period.
  
  
  RESULTS
  Twenty-three women completed the study (mean age 60.6 +/- 8.3 years). There was no effect of tamoxifen on clinic BP (mean difference between withdrawal and continuation for systolic BP, 0.4 +/- 8.4 mm Hg, 95% confidence interval [CI] -4.0 to 3.2, and diastolic 0.6 +/- 4.7, 95%CI -1.4 to 2.7) or 24-hour ambulatory BP (systolic 0.7 +/- 7.4 mmHg, 95%CI -2.6 to 3.9; diastolic BP, 1.9 +/- 5.5, 95% CI -0.5 to 4.2). Furthermore, no effect of tamoxifen on PRA (mean difference between withdrawal and continuation 0.03 +/- 0.5 ng/mL/h, 95% CI -0.3 to 0.2) or FENa (0.05 +/- 0.5, 95% CI -0.2 to 0.2) was detected.
  
  
  CONCLUSIONS
  Tamoxifen seems to have no effect on BP, PRA, or FE(Na) in normotensive postmenopausal women.
authors.affiliation: Hypertension Center, Third University Department of Medicine, Sotiria Hospital, Athens, Greece. gssterg@hol.gr
authors.forename: George S
authors.initials: GS
authors.lastname: Stergiou
authors.forename: Andromachi S
authors.initials: AS
authors.lastname: Zourbaki
authors.forename: Stamatis P
authors.initials: SP
authors.lastname: Efstathiou
authors.forename: George P
authors.initials: GP
authors.lastname: Stathopoulos
authors.forename: Antonios D
authors.initials: AD
authors.lastname: Keramopoulos
authors.forename: Theodore D
authors.initials: TD
authors.lastname: Mountokalakis
mesh_terms: D000368:Aged; D001794:Blood Pressure / Q000187:drug effects*; D018660:Blood Pressure Monitoring, Ambulatory; D018592:Cross-Over Studies; D004965:Estrogen Antagonists / Q000494:pharmacology*; D005260:Female; D006801:Humans; D008875:Middle Aged; D017698:Postmenopause / Q000097:blood / Q000652:urine; D012083:Renin / Q000097:blood; D012964:Sodium / Q000652:urine; D013629:Tamoxifen / Q000494:pharmacology*
chemical_list: D004965:Estrogen Antagonists; D013629:Tamoxifen; D012964:Sodium; D012083:Renin