title: Pyridostigmine in the treatment of postural orthostatic tachycardia: a single-center experience.
abstract: BACKGROUND
  The long-term efficacy of pyridostigmine, a reversible acetyl cholinesterase inhibitor, in the treatment of postural orthostatic tachycardia syndrome (POTS) patients remains unclear. We report our retrospective, single-center, long-term experience regarding the efficacy and adverse effect profile of pyridostigmine in the treatment of POTS patients.
  
  
  METHODS
  This retrospective study included an extensive review of electronic charts and data collection in regards to patient demographics, orthostatic parameters, side-effect profile, subjective response to therapy, as well as laboratory studies recorded at each follow-up visit to our institution's Syncope and Autonomic Disorders Center. The response to pyridostigmine therapy was considered successful if patient had both symptom relief in addition to an objective response in orthostatic hemodynamic parameters (heart rate [HR] and blood pressure). Three hundred patients with POTS were screened for evaluation in this study. Of these 300, 203 patients with POTS who received pyridostigmine therapy were reviewed. Of these 203 patients, 168 were able to tolerate the medication after careful dose titration. The mean follow-up duration in this group of patients was 12 ± 3 (9-15) months. Pyridostigmine improved symptoms of orthostatic intolerance in 88 of 203 (43%) of total patients or 88 of 172 (51%) who were able to tolerate the drug. The symptoms that improved the most included fatigue (55%), palpitations (60%), presyncope (60%), and syncope (48%). Symptom reduction correlated with a statistically significant improvement in upright HR and diastolic blood pressure after treatment with pyridostigmine as compared to their baseline hemodynamic parameters (standing HR 94 ± 19 vs 82 ± 16, P < 0.003, standing diastolic blood pressure 71 ± 11 vs 74 ± 12, P < 0.02). Gastrointestinal problems were the most common adverse effects (n = 39, 19%) reported. The overall efficacy of pyridostigmine in our study was seen in 42% of total patients or 52% of patients who could tolerate taking the drug.
  
  
  CONCLUSIONS
  The subgroup of POTS patients who can tolerate oral pyridostigmine may demonstrate improvement in their standing HR, standing diastolic blood pressure, and clinical symptoms of orthostatic intolerance.
authors.affiliation: Electrophysiology Section, Division of Cardiology, Department of Medicine, The University of Toledo, Toledo, Ohio 43614, USA.
authors.forename: Khalil
authors.initials: K
authors.lastname: Kanjwal
authors.forename: Beverly
authors.initials: B
authors.lastname: Karabin
authors.forename: Mujeeb
authors.initials: M
authors.lastname: Sheikh
authors.forename: Lawrence
authors.initials: L
authors.lastname: Elmer
authors.forename: Yousuf
authors.initials: Y
authors.lastname: Kanjwal
authors.forename: Bilal
authors.initials: B
authors.lastname: Saeed
authors.forename: Blair P
authors.initials: BP
authors.lastname: Grubb
mesh_terms: D002800:Cholinesterase Inhibitors / Q000627:therapeutic use; D005260:Female; D006801:Humans; D008297:Male; D054972:Postural Orthostatic Tachycardia Syndrome / Q000175:diagnosis* / Q000188:drug therapy*; D011729:Pyridostigmine Bromide / Q000627:therapeutic use*; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D002800:Cholinesterase Inhibitors; D011729:Pyridostigmine Bromide