The University of Oxford in the UK has reported that the nationwide Platform Randomised trial of INterventions against Covid-19 in older people (PRINCIPLE) trial found that antibiotics azithromycin and doxycycline are not generally effective treatments for Covid-19.

The PRINCIPLE trial is led from the Primary Care Clinical Trials Unit at the University of Oxford’s Nuffield Department of Primary Care Health Sciences.

It has a flexible, platform design to analyse various potential Covid-19 therapies for use in the community to aid people in recovering faster and alleviating the need for hospital admission.

In the trial, 526 subjects received azithromycin 500mg once daily for three days within the 14 days of onset of Covid-19 and were compared with 862 subjects receiving usual care.

Meanwhile, 798 subjects were randomised to receive doxycycline 200mg on the first day followed by 100mg a day for six days within the first 14 days of Covid-29 onset and analysed with 994 subjects receiving usual care.

The independent Trial Steering Committee reviewed the interim analyses data of the azithromycin and doxycycline arms of the trial.

It advised the trial investigators that no beneficial effect of either antibiotic in subjects aged over 50 years who were treated at home in the early stages of Covid-19 was observed.

Data showed that none of the treatments lowered the time taken for patients to first report that they feel recovered sufficiently to achieve meaningful clinical benefit.

The University of Oxford Nuffield Department of Primary Care Health Sciences and trial co-lead professor Chris Butler said: “Azithromycin and doxycycline have anti-inflammatory, antibacterial and possibly antiviral effects, and so were considered as potential treatments for Covid-19 in the community.

“While we are completing the analysis of the full range of study outcomes, and in different patient groups, our findings show that a three-day course of azithromycin or a seven-day course of doxycycline has no important clinical benefit in terms of the time taken to feeling recovered, and so will not help most patients with COVID-19 in the early stages their illness.”

Last May, a new clinical trial was launched in the UK to study pre-existing drugs as potential Covid-19 therapies in people aged more than 50 years with signs of the infection.