For the millions suffering from the crushing fatigue and brain fog of long COVID, new hope may come from an unlikely source—a drug used mainly for Parkinson’s patients.
Amantadine, a medication that reduces involuntary movements, was recently found to significantly cut long COVID fatigue levels in just two weeks. Considering up to 6.9 percent of American adults now battle the wrath of this post-viral syndrome, the discovery of amantadine’s effects may prove a critical advance.
Two-Week Trial Cut Fatigue Scores by Over Half
While chronic fatigue is the most common symptom of long COVID, scientists still don’t fully understand why or how it persists in the body, according to the randomized, open-label clinical trial, published in Scientific Reports.
Some research indicates issues with the glymphatic system, which removes waste from the central nervous system, while other studies suggest problems with neurotransmitters or inflammation in functional brain tissue.
With this limited understanding of the mechanisms behind chronic fatigue, the research team studied 62 patients to determine whether amantadine could alleviate their symptoms. The Iran-based team hypothesized the medication may be effective given its known ability to reduce fatigue in multiple sclerosis patients.
Nearly two-thirds of the study participants were female (62.9 percent), with an average age of 37. Close to half had been hospitalized for COVID-19 in fall the fall of 2022. All patients had experienced debilitating fatigue for 30 to 60 days and had scored high on tiredness tests.
The researchers divided patients into two groups. One group received 100 mg of Amantadine twice daily, morning and evening. The control group received no medication. Usage of other medications was not allowed. After two weeks, the amantadine group showed significantly improved fatigue symptoms compared to the control group.
Before the trial started, on the Visual Fatigue Scale, the amantadine group scored 7.90 out of 10 and the control group scored 7.34. On the Fatigue Severity Scale, the amantadine group scored 53.10 and the control group scored 50.38.
After two weeks, on the Visual Fatigue Scale, the Amantadine group dropped to 3.37 while the control group only dropped to 5.97. And, on the Fatigue Severity Scale, the amantadine group dropped to 28.40 while the control group only dropped to 42.59.
“Given the high incidence rate of post-COVID-19 fatigue and lack of treatment option, the satisfactory result obtained in our study with treatment of Amantadine is considerable,” the researchers wrote.
Why Amantadine Could Work for Long COVID
This study is not the first evidence of Amantadine’s effectiveness against long COVID. In fact, a May 2022 study published in ScienceDirect demonstrated this drug can prevent progression of COVID-19 symptoms.
Amantadine provides multiple therapeutic effects. It has antiviral and anti-inflammatory properties. Additionally, it stimulates dopamine receptors, potentially alleviating cognitive impairment. Through its antiviral mechanisms, amantadine inhibits early viral replication, which is why it has been used as an influenza A treatment.
In the current study, patients tolerated amantadine well over a two-week period. However, those taking it for eight weeks discontinued use due to intolerance of longer-term side effects like nausea, vomiting, dry mouth, constipation, appetite changes, abnormal dreams, insomnia, and headaches.
The drug is said to be well-absorbed when taken by the mouth and tolerated well by the stomach. The recommended dose is 100 mg a day, twice a day for two weeks.
According to the National Institutes of Health, children and adolescents also tolerate amantadine well, suggesting it could benefit the 1.3 percent of U.S. children with long COVID diagnoses.