Melatonin reduces tachycardia in postural tachycardia syndrome: a randomized, crossover trial.
BACKGROUND
Postural tachycardia syndrome (POTS) induces disabling chronic orthostatic intolerance with an excessive increase in heart rate (HR) upon standing, and many POTS patients have a hyperadrenergic state. Medications that restrain HR are a promising approach to this problem.


OBJECTIVE
We tested the hypothesis that melatonin will attenuate the tachycardia and improve symptom burden in patients with POTS.


METHODS
Patients with POTS (n = 78) underwent acute drug trials with melatonin 3 mg orally and placebo, on separate mornings, in a randomized crossover design. Blood pressure, HR, and symptoms were assessed while seated and after standing for up to 10 min prior to, and hourly for 4 h following study drug administration.


RESULTS
The reduction in standing HR was significantly greater 2 h after melatonin compared with placebo (P = 0.017). There was no significant difference in the reduction of systolic blood pressure between melatonin and placebo, either with standing or while seated. The symptom burden was not improved with melatonin compared with placebo.


CONCLUSIONS
Oral melatonin produced a modest decrease in standing tachycardia in POTS. Further research is needed to determine the effects of regular night-time use of this medication in POTS.
Division of Clinical Pharmacology, Department of Medicine, Autonomic Dysfunction Center, Vanderbilt University, Nashville, TN, USA.
Elizabeth A
EA
Green
Bonnie K
BK
Black
Italo
I
Biaggioni
Sachin Y
SY
Paranjape
Kanika
K
Bagai
Cyndya
C
Shibao
Mirian C
MC
Okoye
William D
WD
Dupont
David
D
Robertson
Satish R
SR
Raj
D000284:Administration, Oral; D000328:Adult; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects; D018592:Cross-Over Studies; D004334:Drug Administration Schedule; D005260:Female; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D008297:Male; D008550:Melatonin / Q000008:administration & dosage / Q000627:therapeutic use*; D009638:Norepinephrine / Q000097:blood; D054972:Postural Orthostatic Tachycardia Syndrome / Q000175:diagnosis / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D013564:Sympathetic Nervous System / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology; D013714:Tennessee; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
D000889:Anti-Arrhythmia Agents; D008550:Melatonin; D009638:Norepinephrine
Autonomic nervous system; Drugs; Melatonin; Orthostatic intolerance; Sympathetic nervous system; Tachycardia