Antihistamines improve cardiovascular manifestations and other symptoms of long-COVID attributed to mast cell activation

Abstract

IntroductionLong-COVID is a broadly defined condition and there are no effective therapies. Cardiovascular manifestations of long-COVID include high heart rate, postural tachycardia, and palpitations. 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.MethodsIn 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.ResultsLong-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.ConclusionsOur 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.

A diabetic patient increased premature ventricular contractions after using liraglutide: a case report

“…We hypothesize that the increase in ventricular premature beats in our patient may be related to liraglutide injection, which has been the subject of fewer previous studies and reports. Additionally, the cause of the arrhythmia may be related to alterations in sympathovagal balance, including a drop in blood pressure in vasovagal syncope ( 9 ), and mimetic sympathetic activation after excess histamine production ( 10 ). Askin L et al ( 11 ) reported that assessment of ambulatory blood pressure (ABP) and heart rate variability (HRV) in patients with premature ventricular contractions (PVCs) is part of a comprehensive approach to the assessment of cardiovascular regulation.…”

“…The resting electrocardiogram showed sinus rhythm, suspected ST segment elevation ≤0.05 mv in leads Ⅱ and aVF, frequent premature ventricular contractions, and negative troponin, myoglobin, and creatine kinase isoenzyme. On April 13, the patient's electrocardiogram showed: average heart rate: 79 beats/min, sinus rhythm, occasional atrial premature beats, frequent ventricular premature beats, ventricular premature beats: 10,229 beats, ST-T alteration, heart rate variability analysis: heart rate variability indices SDNN (50), SDANN (47), RMSSD (10), PNN50 (0) decreased (Figure 2). On April 14, liraglutide was stopped and insulin glulisine was given subcutaneously 6 U in the morning, 4 U in the evening and 4 U before meals.…”

Microvascular Capillary and Precapillary Cardiovascular Disturbances Strongly Interact to Severely Affect Tissue Perfusion and Mitochondrial Function in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Evolving from the Post COVID-19 Syndrome

“…(3B) Histamine: the high prevalence of allergies and mast cell overactivation, which might even be augmented by SARS-CoV-2-infection, particularly in the gut, and the fact that histamine has a strong vasodilator effect on veins in humans [3,15,[29][30][31] warrant further discussion. The most convincing evidence for the involvement of histamine is the alleviating effect of long-term symptoms of Post-COVID-19 infection by antihistamine treatment [32][33][34][35][36]. From a theoretical point of view, the dilating effect of histamine on human veins may be particularly detrimental if the capacitance vessels or veins are already weakened or structurally distended as in EDS or Marfan Syndrome, or damaged by the mechanisms after COVID-19 infection [15].…”

Long COVID management: a mini review of current recommendations and underutilized modalities

“…Many current strategies include self-management and rehabilitation. Proposed treatments include: apheresis ( 8 ), nirmatrelvir/ritonavir (Paxlovid) ( 9 ), antihistamines such as loratadine ( 10 ), fexofenadine, and famotidine ( 11 ), anticoagulants such as apixaban ( 10 ) and antiplatelet agents such as aspirin and clopidogrel ( 12 ). Thrombolytics such as nattokinase, serrapeptase, lumbrokinase, and bromelain have also been proposed as potential treatments for long COVID ( 13 ).…”