Modafinil Increases Blood Pressure, but not Heart Rate, and does not worsen Symptoms in Postural Tachycardia Syndrome (POTS)
HRS Meeting Name
Heart Rhythm On Demand 2013
Satish R. Raj, MD, MSCI, FHRS
Clinical Electrophysiology & Catheter Ablation
Syncope and the Autonomic Nervous System
Session Date and Time
Thursday, May 9, 2013, 1:30 PM
Introduction: Postural tachycardia syndrome (POTS) is characterized by an excessive heart rate (HR) increase >30 bpm on standing. Many POTS patients have neurocognitive complaints with memory problems and an inability to concentrate (“brain fog”). We have previously reported that POTS patients have attention deficits which could produce significant impairments in their quality of life. Modafinil is a stimulant narcolepsy drug used to treat attention deficit disorder. Since many stimulants increase sympathetic nervous system activity, there is concern that modafinil might exacerbate standing HR and worsen orthostatic symptoms in POTS patients. We prospectively tested the acute effects of modafinil on tachycardia and symptoms in POTS.
Methods: Patients with POTS (n=52;48 female,32±10 years) underwent a randomized single-blind crossover trial with oral modafinil 100 mg and placebo on separate mornings in a post-absorptive and drug-free state. Non-invasive HR and blood pressure (BP) were measured with the patient
seated comfortably. At baseline, and hourly for 4h post-medication, the patients stood for up to 10 min, and their standing HR & BP were recorded. Symptoms were self-recorded every 2 hours. Only complete datasets for each parameter were analyzed in the repeated measures general linear model. Data are presented as mean±SD. PINT represents the interaction of drug*time.
Results: The standing HR decreased from baseline (B) to 4h post drug for both modafinil (B:112±14 bpm, 4h:105±16 bpm) and placebo (B:113±14 bpm, 4h:102±16 bpm), but the these were not significantly different from each other (PDRUG=0.328; PINT=0.059). The standing systolic BP increased significantly more with modafinil (B:106±15 mmHg, 4h:115±14 mmHg) than placebo (B:108±14 mmHg, 4h:111±15 mmHg; PDRUG=0.004; PINT=0.018). Neither modafinil (B:15±10 bpm, 4h:14±12 bpm) nor placebo (B:18±16 bpm, 4h:14±12 bpm) increased the symptom burden (PINT=0.307).
Conclusions: Modafinil, a stimulant used by some POTS patients for neurocognitive complaints, increases standing BP, but not standing HR. Importantly, modafinil did not increase the symptom burden. These data suggest that this stimulant could be a promising agent for use in POTS patients if its neurocognitive benefits can be demonstrated