Positive impact of oral hydroxychloroquine and povidone-iodine throat spray for COVID-19 prophylaxis: an open-label randomized trial
Seet et al.
, Positive impact of oral hydroxychloroquine and povidone-iodine throat spray for COVID-19 prophylaxis: an..
, International Journal of Infectious Diseases, doi:10.1016/j.ijid.2021.04.035, NCT04446104
Prophylaxis RCT in Singapore with 3,037 low risk patients, showing lower serious cases, lower symptomatic cases, and lower confirmed cases of COVID-19 with all treatments (ivermectin, HCQ, PVP-I, and Zinc + vitamin C) compared to vitamin C.
Meta-analysis of vitamin C in 6 previous trials shows a benefit of 16%, so the actual benefit of ivermectin, HCQ, and PVP-I may be higher. Cluster RCT with 40 clusters.
There were no hospitalizations and no deaths. NCT04446104 (history)
risk of symptomatic case, 44.7% lower, RR 0.55, p = 0.002, treatment 42 of 735 (5.7%), control 64 of 619 (10.3%), NNT 22.
risk of case, 31.1% lower, RR 0.69, p = 0.01, treatment 338 of 735 (46.0%), control 433 of 619 (70.0%), NNT 4.2, adjusted per study, odds ratio converted to relative risk, model 6.
Effect extraction follows pre-specified rules prioritizing more serious outcomes. Submit updates
Seet et al., 14 Apr 2021, Cluster Randomized Controlled Trial, Singapore, peer-reviewed, 15 authors, this trial compares with another treatment - results may be better when compared to placebo, trial NCT04446104 (history)
Abstract: International Journal of Infectious Diseases 106 (2021) 314–322
Contents lists available at ScienceDirect
International Journal of Infectious Diseases
journal homepage: www.elsevier.com/locate/ijid
Positive impact of oral hydroxychloroquine and povidone-iodine
throat spray for COVID-19 prophylaxis: An open-label randomized
Raymond Chee Seong Seeta,b,* , Amy May Lin Queka,b , Delicia Shu Qin Ooic,d,
Sharmila Senguptae , Satish Ramapatna Lakshminarasappaf , Chieh Yang Koog ,
Jimmy Bok Yan Soh , Boon Cher Gohi , Kwok Seng Lohj, Dale Fishera,e, Hock Luen Teoha,b ,
Jie Sunk , Alex R. Cookk , Paul Anantharajah Tambyaha,e, Mikael Hartmanh,k
Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
Division of Neurology, Department of Medicine, National University Hospital, Singapore
Department of Pediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
Division of Pediatric Endocrinology, Khoo Teck Puat-National University Children’s Medical Institute, National University Hospital, Singapore
Division of Infectious Diseases, Department of Medicine, National University Hospital, Singapore
Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
Department of Cardiology, National University Heart Centre, Singapore
Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
Department of Hematology-Oncology, National University Cancer Institute, Singapore
Department of Otolaryngology-Head and Neck Surgery, National University Hospital, Singapore
Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
A R T I C L E I N F O
A B S T R A C T
Received 30 March 2021
Received in revised form 8 April 2021
Accepted 9 April 2021
Background: We examined whether existing licensed pharmacotherapies could reduce the spread of
coronavirus disease 2019 (COVID-19).
Methods: An open-label parallel randomized controlled trial was performed among healthy migrant
workers quarantined in a large multi-storey dormitory in Singapore. Forty clusters (each deﬁned as
individual ﬂoors of the dormitory) were randomly assigned to receive a 42-day prophylaxis regimen of
either oral hydroxychloroquine (400 mg once, followed by 200 mg/day), oral ivermectin (12 mg once),
povidone-iodine throat spray (3 times/day, 270 mg/day), oral zinc (80 mg/day)/vitamin C (500 mg/day)
combination, or oral vitamin C, 500 mg/day. The primary outcome was laboratory evidence of SARS-CoV2 infection as shown by either: (1) a positive serologic test for SARS-CoV-2 antibody on day 42, or (2) a
positive PCR test for SARS-CoV-2 at any time between baseline and day 42.
Results: A total of 3037 asymptomatic participants (mean age, 33.0 years; all men) who were seronegative
to SARS-CoV-2 at baseline were included in the primary analysis. Follow-up was nearly complete (99.6%).
Compared with vitamin C, signiﬁcant absolute risk reductions (%, 98.75% conﬁdence interval) were
observed for oral hydroxychloroquine (21%, 2–42%) and povidone-iodine throat spray (24%, 7–39%). No
statistically signiﬁcant differences were observed with oral zinc/vitamin C combination (23%, –5 to +41%)
and ivermectin (5%, –10 to +22%). Interruptions due to side effects were highest among participants who
received zinc/vitamin C combination (6.9%), followed by vitamin..
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