Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

As the world waits impatiently for a COVID-19 vaccine, an exhaustive review of hydroxychloroquine and chloroquine pharmacology suggests that the doses used in COVID-19 prevention trials are safe, say University of Oxford affiliated researchers in a study published in PLoS Medicine.

None © 2020 MORU. Photographer: Supa-at Asarath.

“Hydroxychloroquine and chloroquine have become intensely politicised during the COVID-19 pandemic. It has been really hard for the public to separate fact from fiction“  said study co-author Assoc Prof Phaik Yeong Cheah, head of ethics and public engagement at the Mahidol Oxford Tropical Medicine Research Unit (MORU), Bangkok Thailand.

“There has been a lot of concern that hydroxychloroquine and chloroquine might be toxic, but using pharmacokinetic-pharmacodynamic information from healthy volunteers, patients with malaria and those with rheumatological diseases, as well as people who intentionally took overdoses, we show that the doses used in COVID-19 prevention and most treatment trials are very likely to be safe,” said study co-author Prof Joel Tarning, Head of Clinical Pharmacology at MORU.

Used for over 60 years to treat malaria, amoebic liver abscess and rheumatological conditions like lupus, billions of hydroxychloroquine or chloroquine treatments have been given. These drugs have recently been shown in the laboratory to kill the novel coronavirus (SARS-CoV-2), the virus that causes COVID-19. Hydroxychloroquine does not benefit patients hospitalised with COVID-19 infection, but studies have not examined whether it could work as prevention, where it has a much greater chance of being effective.

Unfortunately, because the whole subject has become so highly charged, say the scientists, large clinical trials like COPCOV – a global study to test if hydroxychloroquine and chloroquine can prevent COVID-19 in healthcare workers – are not being sufficiently promoted or supported. The prevention studies urgently need participants.

“I don’t know if hydroxychloroquine can prevent COVID-19 or not,” said study co-author Prof Sir Nick White, Co-Principal Investigator of the Oxford-led COPCOV clinical trial. “But I do know that we really need to find out, and quickly. All the negative publicity has naturally made people reluctant to enrol in studies. We could be waiting a long time for an effective vaccine.”

COPCOV now has 4 sites operating in the UK, with several more coming on line by end September It is the only non-vaccine COVID prophylaxis study badged as being of Urgent Public Health importance by the UK’s NIHR Clinical Research Network.

“We urge anyone working in UK health settings – nurses, care-assistants, doctors, therapists, dentists, dietitians, cleaners, porters, food service workers, phlebotomists, ambulance workers, radiographers – to go to www.copcov.org and enrol in our UK COVID-19 prevention study,” said Prof Martin Llewelyn from Brighton and Sussex Medical School, who as COPCOV UK’s Chief Investigator leads the Trial in the UK along with Prof Amanda Adler, director of the Diabetes Trials Unit within the Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM).

“We know that as used in COPCOV hydroxychloroquine is safe and there are good reasons to think it could offer valuable protection against COVID-19. It’s imperative that COPCOV finds out if it does,” said Prof Llewelyn.

To register for COPCOV UK, visit www.copcov.org. To enrol in a UK study site near you, go to: https://www.copcov.org/takepart.html

------------ 

Paper:

COVID-19 prevention and treatment: A critical analysis of chloroquine and hydroxychloroquine clinical pharmacology. White NJ, Watson JA, Hoglund RM, Chan XHS, Cheah PY, Tarning J. PLoS Med 17(9): et003251. https://doi.org/10.1371/journal.pmed.1003252

 

Similar stories

RECOVERY trial closes recruitment to convalescent plasma treatment for patients hospitalised with COVID-19

@Oxford Research

Convalescent plasma has been widely used as a treatment for COVID-19 but to date there has been no convincing evidence of the effect of convalescent plasma on clinical outcomes in patients admitted to hospital with COVID-19. Recruitment to the convalescent plasma arm of the RECOVERY trial has now closed. The preliminary analysis based on 1873 reported deaths among 10,406 randomised patients shows no significant difference in the primary endpoint of 28-day mortality. Recruitment to all other treatment arms – tocilizumab, aspirin, colchicine, and Regeneron’s antibody cocktail – continues as planned.

Check-list recommended to improve reporting of microscopy methods and results in malaria studies

@Oxford MORU Publication Research

A study to explore the variations of how microscopy methods are reported in published malaria studies has recommended standardised procedures should be implemented for methodological consistency and comparability of clinical trial outcomes.

Receiving and responding to community feedback during health system crises in Kenya

KWTRP Publication Research

The responsiveness of a health system is one of its goals, alongside fairness in financing and outcomes. Listening and responding to the public can make a health system stronger and fairer. However, responsiveness is likely to be undermined, especially for vulnerable and marginal populations, in periods of crises such as disease outbreaks. In the current COVID-19 crisis, there has been more focus on health system control interventions, with minimal consideration of community views. KWTRP colleagues in Kenya consider community engagement and citizens feedback channels, concerns raised by the public and how they were handled, and highlight lessons learned.

RECOVERY trial finds no benefit from azithromycin in patients hospitalised with COVID-19

@Oxford Research

Established in March 2020, the RECOVERY trial tests a range of potential treatments for COVID-19, including azithromycin, a widely used antibiotic that also reduces inflammation. The azithromycin arm of the trial was established to determine whether or not the drug has a meaningful benefit among patients hospitalised with COVID-19. A preliminary analysis shows no significant difference in the primary endpoint of 28-day mortality; there was also no evidence of beneficial effects on the risk of progression to mechanical ventilation or length of hospital stay.

The COVID-19 vaccine: do we know enough to end the pandemic?

@Oxford MORU

Blog by Rima Shretta. Preliminary efficacy results from three vaccine candidates currently in Phase 3 trials have shown an efficacy of more than 90% against the development of symptomatic COVID-19. While these results are promising, all vaccines are in relatively early stages of testing. A comprehensive and transparent roadmap is urgently needed, to determine how limited doses of the first vaccines to be licensed will be distributed, together with which groups will initially be prioritized.

New study on the risk of Plasmodium vivax parasitaemia after Plasmodium falciparum malaria

@Oxford MORU Publication Research

A new study quantifying the high risk of Plasmodium vivax parasitaemia after treatment of Plasmodium falciparum malaria aims to identify populations in which a policy of universal radical cure, combining artemisinin-based combination therapy with a hypnozoitocidal antimalarial drug, would be most beneficial.