NIH opens long COVID trials to evaluate treatments for autonomic nervous system dysfunction

March 12, 2024
Part of NIH’s RECOVER Initiative, trials will test at least three treatments for symptoms such as fast heart rate, dizziness and fatigue.

Two phase 2 clinical trials to test the safety and effectiveness of three treatments for adults with autonomic nervous system dysfunction from long COVID have begun.

The autonomic nervous system acts largely unconsciously and regulates bodily functions, such as heart rate, digestion and respiratory rate. Symptoms associated with autonomic nervous system dysfunction have been among those that patients with long COVID say are most burdensome. The trials are part of the National Institutes of Health’s Researching COVID to Enhance Recovery (RECOVER) Initiative, a nationwide research program to fully understand, diagnose and treat long COVID. Other RECOVER phase 2 clinical trials testing treatments to address viral persistence and neurological symptoms, including cognitive dysfunction (like brain fog), launched in July 2023.

The two trials, collectively known as RECOVER-AUTONOMIC, are testing three potential treatments in adults who, following COVID-19, now have postural orthostatic tachycardia syndrome (POTS). An autonomic nervous system disorder, POTS is characterized by unexpected fast heart rate, dizziness, fatigue or a combination of these symptoms when a person stands up from sitting or lying down. 

The trials will initially examine three potential treatments:

  • Gamunex-C, a form of intravenous immunoglobulin (IVIG), contains antibodies to help the body protect itself against infection from various diseases and is given by intravenous infusion.
  • Ivabradine, an oral medication that reduces heart rate.
  • Coordinator-guided, non-drug care, which includes a series of activities managed through weekly phone calls with a care coordinator, such as wearing a compression belt and eating a high-salt diet, which are recommended for patients with POTS to counteract excessive loss of fluids.  

Participants will first be randomly assigned to receive either IVIG, ivabradine or a placebo. Participants will then be randomly assigned a second time to receive either coordinator-guided, non-drug care or what is considered the usual non-drug care for POTS following COVID-19, such as diet and lifestyle recommendations. RECOVER-AUTONOMIC is an adaptive clinical trial, meaning if additional potential interventions emerge, they can quickly be added and studied in the trial.

Researchers plan to enroll 380 total participants at 50 sites across the United States. Teams at the trial sites will recruit participants from their health systems and surrounding communities. The current list of sites for the trials can be found on (search: NCT06305793, NCT06305806 and NCT06305780) and additional sites will be added to this list as they begin enrolling participants.

NIH release