Antihistaminika

Aus den Erfahrungen mit der aktuen COVID-Infektion gibt es Vermutungen, dass Antihystaminika (genauer H1 and H2 receptor blocker) wirksame Medikamente sein könnten. Für Post-Covid gibt es anekdotische Berichte und erste kleine Studien , dass Antihystaminika gegen Brain Fog helfen.

Mainstream Artikel dazu: https://www.heilpraxisnet.de/naturheilpraxis/long-covid-vielversprechende-behandlung-mit-antihistaminika-20220214554322/

Die Medikation ist entweder

1. fexofenadine 180 mg once daily taken before dinner and famotidine 40 mg once daily at bedtime. (bei Studie ) oder
2. combination of H1 (loratadine 10 mg two times per day or fexofenadine 180 mg two times per day) and H2 (famotidine 40 mg once daily or nizatidine 300 mg once daily) receptor antagonists (HRAs) for a minimum of 4 weeks (bei Studie )

Retrospektive Studie

Eine rertospektive Studie mit 14 Patienten und 13 Kontrollpersonen zeigt die Wirksamkeit von fexofenadine (180 mg/day) and famotidine (40 mg/day) für 20 Tage:

Previous studies have suggested that mast cell activation (MCA) may play a role in the pathophysiology of long-COVID, including in the mechanisms of its cardiovascular manifestations. The present study aimed to evaluate the effectiveness of a treatment with blockers of histamine receptors in patients with long-COVID who did not respond to other therapies.

Methods: In all, 14 patients (F/M = 9/5; 49.5 ± 11.5 years) and 13 controls (F/M = 8/5; 47.3 ± 8.0 years) with long-COVID symptoms attributed to MCA were evaluated. Patients were treated with fexofenadine (180 mg/day) and famotidine (40 mg/day). Fatigue, brain fog, abdominal disorders, and increased heart rate were evaluated in treated and untreated patients at baseline and 20 days later.

Results: Long-COVID symptoms disappeared completely in 29% of treated patients. There was a significant improvement in each of the considered symptoms (improved or disappeared) in all treated patients, and the improvement grade was significantly greater in treated patients compared to controls. No significant differences in the outcomes were observed in the controls.

Conclusions: Our data confirm that histamine receptors blockade may be an effective target to successfully treat long-COVID. Our finding supports the underlying role of MCA in the pathophysiology of long-COVID.

Prospektive Studie

Noch eine detailliertere prospektive beobachtende Studie (49 Patienten, 16 Kontrollpersonen):

• This observational study demonstrates clear symptomatic improvement in response to combined H1/H2 receptor blockade.
• Long COVID is associated with characteristic and specific alterations in circulating T cells that persist for up to 400 days after the initial COVID-19 infection.
• T cell immunophenotyping may provide a rapid and high-throughput diagnostic test for long COVID.

Long COVID is characterized by the emergence of multiple debilitating symptoms following SARS-CoV-2 infection. Its etiology is unclear and it often follows a mild acute illness. Anecdotal reports of gradual clinical responses to histamine receptor antagonists (HRAs) suggest a histamine-dependent mechanism that is distinct from anaphylaxis, possibly mediated by T cells, which are also regulated by histamine. T cell perturbations have been previously reported in post-viral syndromes, but the T cell landscape in patients who have recovered from mild COVID-19 and its relationship to both long COVID symptoms and any symptomatic response to HRA remain underexplored. We addressed these questions in an observational study of 65 individuals who had recovered from mild COVID-19. Participants were surveyed between 87 and 408 days after the onset of acute symptoms; none had required hospitalization, 16 had recovered uneventfully, and 49 had developed long COVID. Symptoms were quantified using a structured questionnaire and T cell subsets enumerated in a standard diagnostic assay. Patients with long-COVID had reduced CD4+ and CD8+ effector memory (EM) cell numbers and increased PD-1 (programmed cell death protein 1) expression on central memory (CM) cells, whereas the asymptomatic participants had reduced CD8+ EM cells only and increased CD28 expression on CM cells. 72% of patients with long COVID who received HRA reported clinical improvement, although T cell profiling did not clearly distinguish those who responded to HRA. This study demonstrates that T cell perturbations persist for several months after mild COVID-19 and are associated with long COVID symptoms.