Treatment of COVID-19 Patients with Quercetin: A Prospective, Single -
Centre, Randomized, Controlled Trial
Abstract
Aim The present study aimed to evaluate the effect of quercetin in
COVID-19 treatment. Methods This was a single-centre, prospective
randomised controlled cohort study. Routine care versus QCB (quercetin,
vitamin C, bromelain) supplementation was compared between 447 patients
with at least one chronic disease and moderate-to-severe respiratory
symptoms. Demographic features, signs, laboratory results and drug
administration data of patients were recorded. The endpoint was that QCB
supplementation was continued throughout the follow-up period from study
baseline to discharge, intubation, or death. Results The most common
complaints at presentation were fatigue (62.4%), cough (61.1%),
anorexia (57%), thirst (53.7%), respiratory distress (51%) and chills
(48.3%). The decrease in CRP, procalcitonin and ferritin levels was
higher in the QCB group (all Ps were <0.05). In the QCB group,
an increase in platelet and lymphocyte counts were higher (all Ps were
<0.05). QCB did not reduce the risk of events during
follow-up. Adjustments for statistically significant parameters,
including the lung stage, use of favipiravir and presence of comorbidity
did not change the results. While there was no difference between the
groups in terms of event frequency, QCB group had more advanced
pulmonary findings. QCB supplement is shown to have a positive effect on
laboratory recovery. Conclusion We suggest that suboptimal
bioavailability of QCB may explain this. So, we conclude that if a
stable blood level can be achieved for QCB, it may make a difference in
the treatment of COVID-19.