Treatments explored to ease postviral symptoms of ME/CFS and long COVID

A variety of treatments, most already commercially available, are under investigation for treating the constellation of overlapping symptoms associated with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), “long COVID,” and dysautonomia.

At the virtual annual meeting of the International Association for Chronic Fatigue Syndrome/Myalgic Encephalomyelitis, speakers presented data for a variety of approaches to ease symptoms common across postviral conditions, such as extreme fatigue, postexertional malaise (“crash”), cognitive dysfunction (“brain fog”), orthostatic intolerance including postural orthostatic tachycardia syndrome (POTS), and chronic pain. Most of the modalities are already commercially available for other indications, although some are costly and not covered by payers for these conditions.

“Both post–acute COVID-19 syndrome and ME/CFS are forms of postinfectious viral syndromes and they have overlapping symptoms. ... In the past, patients were told ‘you have chronic fatigue syndrome but there’s nothing we can do for it.’ That certainly is not the case. There aren’t cures, but there are many management techniques to improve symptoms,” Charles W. Lapp, MD, medical director of the Hunter-Hopkins Center, Charlotte, N.C., said in an interview.

A current mainstay of treatment for ME/CFS – including that triggered by COVID-19 – is activity pacing, in which patients learn to stay within their “energy envelopes” in order to avoid postexertional malaise, a worsening of all symptoms with exertion. The use of “graded exercise” is no longer recommended, per U.K. and U.S. guidelines.

Data for the following approaches were presented at the IACFS/ME conference:

Pyridostigmine (mestinon, others)

Pyridostigmine, an acetylcholinesterase inhibitor, is approved for the treatment of muscle weakness resulting from myasthenia gravis and is available in generic form. It has previously been shown to produce significant improvement in both symptom burden and heart rate response in POTS.

At the IACFS/ME conference, David M. Systrom, MD, a pulmonary and critical care medicine specialist at Brigham and Women’s Hospital and director of the Massachusetts General Hospital Cardiopulmonary laboratory, both in Boston, summarized his group’s study in patients with ME/CFS using pyridostigmine as both a potential treatment for improving exercise capacity and a proof-of-concept that neurovascular dysregulation underlies exertional intolerance in the condition.

A total of 45 patients were randomized to 60 mg oral pyridostigmine or placebo after an invasive cardiopulmonary exercise test, and a second test performed 50 minutes later. Peak VO₂ increased after pyridostigmine but decreased after placebo (+13.3 mL/min vs. –40.2 mL/min, P < .05). Cardiac output and right atrial pressure were also significantly improved with pyridostigmine and worse with placebo.

“We suggest that treatable neurovascular dysregulation underlies acute exercise intolerance in ME/CFS. ... Pyridostigmine may be a useful repurposed off-label treatment [for] a subset of patients with exercise intolerance,” Dr. Systrom said.

Asked to comment, Dr. Lapp said: “We’ve used Mestinon for years because it helps with POTS and also with neurally mediated hypotension. Systrom is taking it to a new level because he’s shown that it increases preload to the heart.” However, he noted that it’s unclear whether the drug will help patients who don’t have POTS specifically. On the other hand, patients rarely experience side effects from the drug.

Since the generic tablets come only in 60-mg doses, and the starting dose is 30 mg three times a day, he advised cutting the tablets in half during titration up to 60 mg three times a day.