title: Effects of norepinephrine reuptake inhibition on postural tachycardia syndrome.
abstract: BACKGROUND
  Postural tachycardia syndrome (POTS) is a disorder of chronic orthostatic intolerance accompanied by excessive orthostatic tachycardia. Patients with POTS commonly have comorbid conditions such as attention deficit hyperactivity disorder, depression, or fibromyalgia that are treated with medications that inhibit the norepinephrine reuptake transporter (NRI). NRI medications can increase sympathetic nervous system tone, which may increase heart rate (HR) and worsen symptoms in POTS patients. We sought to determine whether NRI with atomoxetine increases standing tachycardia or worsens the symptom burden in POTS patients.
  
  
  RESULTS
  Patients with POTS (n = 27) underwent an acute drug trial of atomoxetine 40 mg and placebo on separate mornings in a randomized, crossover design. Blood pressure (BP), HR, and symptoms were assessed while seated and after standing prior to and hourly for 4 hours following study drug administration. Atomoxetine significantly increased standing HR compared with placebo (121 ± 17 beats per minute versus 105 ± 15 beats per minute; P = 0.001) in POTS patients, with a trend toward higher standing systolic BP (P = 0.072). Symptom scores worsened with atomoxetine compared to placebo (+4.2 au versus -3.5 au; P = 0.028) from baseline to 2 hours after study drug administration.
  
  
  CONCLUSIONS
  Norepinephrine reuptake inhibition with atomoxetine acutely increased standing HR and symptom burden in patients with POTS.
authors.affiliation: Autonomic Dysfunction Center, Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University, Nashville, TN.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Green
authors.forename: Vidya
authors.initials: V
authors.lastname: Raj
authors.forename: Cyndya A
authors.initials: CA
authors.lastname: Shibao
authors.forename: Italo
authors.initials: I
authors.lastname: Biaggioni
authors.forename: Bonnie K
authors.initials: BK
authors.lastname: Black
authors.forename: William D
authors.initials: WD
authors.lastname: Dupont
authors.forename: David
authors.initials: D
authors.lastname: Robertson
authors.forename: Satish R
authors.initials: SR
authors.lastname: Raj
mesh_terms: D018759:Adrenergic Uptake Inhibitors / Q000494:pharmacology*; D000328:Adult; D000069445:Atomoxetine Hydrochloride; D018592:Cross-Over Studies; D005260:Female; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D008297:Male; D050484:Norepinephrine Plasma Membrane Transport Proteins / Q000037:antagonists & inhibitors*; D054972:Postural Orthostatic Tachycardia Syndrome / Q000503:physiopathology*; D011437:Propylamines / Q000494:pharmacology*; D012720:Severity of Illness Index
chemical_list: D018759:Adrenergic Uptake Inhibitors; D050484:Norepinephrine Plasma Membrane Transport Proteins; D011437:Propylamines; C493227:SLC6A2 protein, human; D000069445:Atomoxetine Hydrochloride
keywords: atomoxetine; autonomic nervous system; drugs; orthostatic intolerance; sympathetic nervous system; tachycardia