The Exercise Response to Pharmacologic Cholinergic Stimulation in Myalgic Encephalomyelitis / Chronic Fatigue Syndrome
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|ClinicalTrials.gov Identifier: NCT03674541|
Recruitment Status : Enrolling by invitation
First Posted : September 17, 2018
Last Update Posted : July 15, 2020
Myalgic encephalomyelitis/Chronic fatigue syndrome (ME/CFS), otherwise known as Chronic fatigue syndrome (CFS) or myalgic encephalomyelitis (ME), is an under-recognized disorder whose cause is not yet understood. Suggested theories behind the pathophysiology of this condition include autoimmune causes, an inciting viral illness, and a dysfunctional autonomic nervous system caused by a small fiber polyneuropathy. Symptoms include fatigue, cognitive impairments, gastrointestinal changes, exertional dyspnea, and post-exertional malaise. The latter two symptoms are caused in part by abnormal cardiopulmonary hemodynamics during exercise thought to be due to a small fiber polyneuropathy. This manifests as low biventricular filling pressures throughout exercise seen in patients undergoing a level 3 CPET along with small nerve fiber atrophy seen on skin biopsy.
After diagnosis, patients are often treated with pyridostigmine (off-label use of this medication) to enhance cholinergic stimulation of norepinephrine release at the post-ganglionic synapse. This is thought to improve venoconstriction at the site of exercising muscles, leading to improved return of blood to the heart and increasing filling of the heart to more appropriate levels during peak exercise. Retrospective studies have shown that noninvasive measurements of exercise capacity, such as oxygen uptake, end-tidal carbon dioxide, and ventilatory efficiency, improve after treatment with pyridostigmine. To date, there are no studies that assess invasive hemodynamics after pyridostigmine administration.
It is estimated that four million people suffer from ME/CFS worldwide, a number that is thought to be a gross underestimate of disease prevalence. However, despite its potential for debilitating symptoms, loss of productivity, and worldwide burden, the pathophysiology behind ME/CFS remains unknown and its treatment unclear. By evaluating the exercise response to cholinergic stimulation, this study will shed further light on the link between the autonomic nervous system and cardiopulmonary hemodynamics, potentially leading to new therapeutic targets.
|Condition or disease||Intervention/treatment||Phase|
|Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Chronic Fatigue Syndrome Myalgic Encephalomyelitis Exercise Intolerance Dysautonomia Low Ventricular Filling Pressures (Preload Failure) Postural Orthostatic Tachycardia Syndrome Orthostatic Hypotension Fibromyalgia||Drug: Pyridostigmine Bromide Drug: Placebo||Phase 2|
The hypothesis of our study is that hemodynamic, ventilatory and oxygen exchange variables such biventricular filling pressures and systemic oxygen extraction can be improved by cholinergic stimulation in patients with ME/CFS.
The objective of this study is to examine the exercise response to pharmacologic cholinergic stimulation in ME/CFS patients already undergoing a clinically indicated level 3 cardiopulmonary exercise test (CPET). This will be achieved by inhibiting acetylcholinesterase with pyridostigmine, thus increasing acetylcholine levels, downstream levels of norepinephrine, and enhancing vascular regulation.
To test our hypothesis, we propose the following specific aims:
Define the response of peak oxygen uptake (VO2) to pyridostigmine. Define the gas exchange responses, such as end-tidal CO2 and ventilatory efficiency to pyridostigmine.
Define the hemodynamic responses, such as right atrial pressures, pulmonary artery pressure, pulmonary capillary wedge pressures, cardiac output, heart rate, stroke volume, pulmonary vascular resistance and systemic vascular resistance to pyridostigmine.
Evaluate the response of skeletal muscle oxygen extraction and lactate to pyridostigmine.
These determinations will occur during a clinically indicated level 3 CPET, which includes exercising on a stationary cycle with a right heart catheter (RHC) and a radial arterial line in place. To stimulate the cholinergic response, a single dose of an oral acetylcholinesterase inhibitor, pyridostigmine, versus placebo will be given after the level 3 CPET. Recovery cycling will be performed after a rest period of 50 minutes. This will be administered in a randomized, double-blind, placebo-controlled trial.
|Study Type :||Interventional (Clinical Trial)|
|Estimated Enrollment :||50 participants|
|Intervention Model:||Parallel Assignment|
|Intervention Model Description:||Subjects will be assigned ramsomly to receive either pyridostigmine or placebo, both study participants and investigators will be blinded.|
|Masking:||Triple (Participant, Care Provider, Investigator)|
|Official Title:||The Exercise Response to Pharmacologic Cholinergic Stimulation in Myalgic Encephalomyelitis / Chronic Fatigue Syndrome|
|Actual Study Start Date :||January 14, 2020|
|Estimated Primary Completion Date :||June 1, 2021|
|Estimated Study Completion Date :||June 1, 2021|
Active Comparator: Study Drug - Pyridostigmine
Pyridostigmine 60 mg by mouth as a one time dose
Drug: Pyridostigmine Bromide
Pyridostigmine Bromide 60 mg capsule by mouth as a one time dose
Other Name: Mestinon
Placebo Comparator: Placebo
Placebo by mouth as a one time dose
Placebo (Cellulose microcrystalline) capsule by mouth as a one time dose
- Maximal Oxygen Uptake (VO2max) [ Time Frame: 1 hour ]Define the response of oxygen uptake to pyridostigmine
- End-tidal Carbon Dioxide (CO2) [ Time Frame: 1 hour ]Define the response of carbon dioxide production to pyridostigmine
- Ventilatory Efficiency (VE/VCO2) [ Time Frame: 1 hour ]Define the ventilatory efficiency response to pyridostigmine
- Right atrial pressure (RAP) [ Time Frame: 1 hour ]Define the right atrial pressure response to pyridostigmine
- Pulmonary artery pressure (PAP) [ Time Frame: 1 hour ]Define the pulmonary artery pressure response to pyridostigmine
- Pulmonary capillary wedge pressure (PCWP) [ Time Frame: 1 hour ]Define the pulmonary capillary wedge pressure response to pyridostigmine
- Cardiac output (CO) [ Time Frame: 1 hour ]Define the cardiac output response to pyridostigmine
- Heart rate (HR) [ Time Frame: 1 hour ]Define the heart rate response to pyridostigmine
- stroke Volume (SV) [ Time Frame: 1 hour ]Define the stroke volume response to pyridostigmine
- Pulmonary vascular resistance (PVR) [ Time Frame: 1 hour ]Define the pulmonary vascular resistance response to pyridostigmine
- Systemic vascular resistance (SVR) [ Time Frame: 1 hour ]Define the systemic vascular resistance response to pyridostigmine
- Arterial venous content difference (Ca-v O2 Difference) [ Time Frame: 1 hour ]Evaluate skeletal muscle oxygen extraction response to pyridostigmine
- Lactate [ Time Frame: 1 hour ]Evaluate the lactate response to pyridostigmine
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03674541
|United States, Massachusetts|
|Brigham and Women's Hospital|
|Boston, Massachusetts, United States, 02215|
|Principal Investigator:||David Systrom, MD||Brigham and Women's Hospital|