Low-Dose Naltrexone Improves post-COVID-19 condition Symptoms

Abstract:

Purpose: Treatments for myalgic encephalomyelitis and chronic fatigue syndrome can be adapted for post-COVID-19 condition. Our aim was to compare treatments in patients from our post-COVID-19 clinic.

Methods: We conducted a retrospective cohort study and included consecutive patients enrolled in our post-COVID-19 clinic. We included patients who received low-dose naltrexone, amitriptyline, duloxetine, and physical therapy, and evaluated improvements in fatigue, pain, dyspnea, and brain fog recorded in the electronic health record. We calculated the adjusted relative hazard of improvement using Cox proportional models. We adjusted for demographic characteristics, comorbidities, and prior COVID-19 hospitalization.

Findings: We included the first 108 patients with post-COVID-19 enrolled in the clinic. Most of the patients received amitriptyline. The relative hazard of improvement for those taking low-dose naltrexone was 5.04 (95% CI, 1.22-20.77; P = 0.02) compared with physical therapy alone. Both fatigue and pain were improved in patients taking low-dose naltrexone; only fatigue was improved in patients taking amitriptyline.

Implications: Post-COVID-19 condition symptoms may improve in patients taking medications adapted from myalgic encephalomyelitis and chronic fatigue syndrome. Randomized controlled trials should evaluate these medications and translational studies should further evaluate their mechanisms of action.

Source: Tamariz L, Bast E, Klimas N, Palacio A. Low-Dose Naltrexone Improves post-COVID-19 condition Symptoms. Clin Ther. 2024 Jan 23:S0149-2918(24)00003-1. doi: 10.1016/j.clinthera.2023.12.009. Epub ahead of print. PMID: 38267326. https://pubmed.ncbi.nlm.nih.gov/38267326/

Amitriptyline and prochlorperazine inhibit proinflammatory mediator release from human mast cells: possible relevance to chronic fatigue syndrome

CFS a complex disorder characterized by unexplained severe fatigue for over 6 months with a broad range of additional symptoms involving the nervous, endocrine and immune systems, and an estimated prevalence of 1%1. Tricyclic antidepressants (TCAs) are prescribed off label for a number of painful diseases that are often comorbid, such as chronic fatigue syndrome (CFS), fibromyalgia, interstitial cystitis, and irritable bowel syndrome, the symptoms of which are worsened by stress2. However, there is no known mechanism to explain the apparent beneficial action of TCAs3.

Mast cells and their mediators have been implicated in inflammatory diseases4, including CFS5. Mast cells are located perivascularly in close proximity to neurons in the thalamus and hypothalamus, especially the median eminence6, where they are juxtaposed to corticotropin-releasing hormone (CRH)-positive nerve processes7. CRH activates mast cells to release vascular endothelial growth factor (VEGF)8, which could participate in neurogenic inflammation and contribute to the pathogenesis of CFS. Such mediators may be released locally in the brain or may cross the blood-brain-barrier (BBB), which can be disrupted by stress, subsequent to mast cell activation9. Given the above, we hypothesized that TCAs may be helpful through inhibition of mast cell release of pro-inflammatory mediators.

You can read the rest of this letter here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3498825/

 

Source: Clemons A, Vasiadi M, Kempuraj D, Kourelis T, Vandoros G, Theoharides TC. Amitriptyline and prochlorperazine inhibit proinflammatory mediator release from human mast cells: possible relevance to chronic fatigue syndrome. J Clin Psychopharmacol. 2011 Jun;31(3):385-7. doi: 10.1097/JCP.0b013e3182196e50. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3498825/ (Full article)

 

Fibromyalgia, chronic fatigue syndrome, and myofascial pain

Abstract:

Epidemiologic studies continue to provide evidence that fibromyalgia is part of a spectrum of chronic widespread pain. The prevalence of chronic widespread pain is several times higher than fibromyalgia as defined by the 1990 American College of Rheumatology guidelines. There is now compelling evidence of a familial clustering of fibromyalgia cases in female sufferers; whether this clustering results from nature or nature remains to be elucidated. A wide spectrum of fibromyalgia-associated symptomatology and syndromes continues to be described.

During the past year the association with interstitial cystitis has been explored, and neurally mediated hypotension has been documented in both fibromyalgia and chronic fatigue syndrome. Abnormalities of the growth hormone-insulin-like growth factor-1 axis have been also documented in both fibromyalgia and chronic fatigue syndrome. The commonly reported but anecdotal association of fibromyalgia with whiplash-type neck trauma was validated in a report from Israel. However, unlike North America, 100% of Israeli patients with posttraumatic fibromyalgia returned to work.

Basic research in fibromyalgia continues to pinpoint abnormal sensory processing as being integral to understanding fibromyalgia pain. Drugs such as ketamine, which block N-methyl-D-aspartate receptors (which are often upregulated in central pain states) were shown to benefit fibromyalgia pain in an experimental setting. The combination of fluoxetine and amitriptyline was reported to be more beneficial than either drug alone in patients with fibromyalgia.

A high prevalence of autoantibodies to cytoskeletal and nuclear envelope proteins was found in chronic fatigue syndrome, and an increased prevalence of antipolymer antibodies was found in symptomatic silicone breast implant recipients who often have fibromyalgia.

 

Source: Bennett R. Fibromyalgia, chronic fatigue syndrome, and myofascial pain. Curr Opin Rheumatol. 1998 Mar;10(2):95-103. http://www.ncbi.nlm.nih.gov/pubmed/9567202

 

Psychotropic treatment of chronic fatigue syndrome and related disorders

Abstract:

BACKGROUND: Chronic fatigue syndrome (CFS) and fibromyalgia frequently are associated with symptoms of major depression. For this reason, antidepressants have been used in treatment of these disorders; however, little direction has been provided into this application in psychopharmacology.

METHOD: First, nine studies were reviewed regarding the relationship of the symptoms of fatigue and depression. Next, 23 reports (12 double-blind studies, 7 open studies, and 4 case reports) were reviewed for the effectiveness of therapy as assessed by global response and improvement of both depression and pain. Studies were differentiated by type of controls, as well as by alleged mechanism of action of the pharmacologic agent.

RESULTS: Disturbances in brain neurochemistry shared by CFS and major depression may serve as a basis for the effectiveness of some antidepressants in CFS. Response to some antidepressants in patients with CFS or fibromyalgia may occur at doses lower than those used in major depression, e.g., amitriptyline 25-75 mg/day. We further found that the more serotonergic treatments (e.g., clomipramine) were more successful in alleviating pain than depression, whereas catecholaminergic agents (e.g., maprotiline, bupropion) seemed particularly effective for symptoms of associated depression.

CONCLUSION: To maximize response of the physiologic and psychological consequences of the disorder, more investigation is needed to replicate the apparent findings that relate the neurochemical impairment underlying CFS and fibromyalgia to the type of antidepressant mechanism.

 

Source: Goodnick PJ, Sandoval R. Psychotropic treatment of chronic fatigue syndrome and related disorders. J Clin Psychiatry. 1993 Jan;54(1):13-20. http://www.ncbi.nlm.nih.gov/pubmed/8428892