An article in the Scientific American by Esther Landhuis reviews the current treatment approaches for COVID-19.
As the highly contagious Omicron variant pushes infections to record highs some two years into the COVID-19 pandemic, physicians in the United States have a growing arsenal of therapies to keep mild disease from worsening.
At the same time, limited availability and challenging logistics are complicating decisions about which patients receive them.
Unfortunately, at this present time in the United Kingdom there are no readily available treatment regimes for outpatients.
Treatments for non-hospitalised patients in the United States.
For newly diagnosed patients at high risk for severe COVID-19, the recommended therapy has generally been monoclonal antibodies. These are lab-made proteins that bind to SARS-CoV-2, the virus that causes COVID, and keeps it from entering and infecting cells. If administered within 10 days of diagnosis, either intravenously or as a series of shots under the skin, monoclonal antibodies can cut hospitalisations and deaths by more than 80%.
Several companies make these treatments which received emergency-use authorisation from the FDA in late 2020. Yet with most COVID cases in the United States currently caused by fast-spreading Omicron, a new coronavirus variant with mutations in the part of SARS-CoV-2 targeted by monoclonals, there is only one antibody that actually works. This is the sotrovimab made by GlaxoSmithKline and Vir Biotechnology. This is administered intravenously as an infusion.
The FDA authorised emergency use of two antiviral treatments which could be taken at home as pills:
- Pfizer’s – Paxlovid
- Merck and Ridgeback Biotherapeutics- Molnupiravir
In studies of high-risk adults who started these treatments within their first five days of COVID symptoms, Paxlovid cut the risk of hospitalisation or death by 89%, and molnupiravir by 30% compared with placebo pills.
One of the concerns with Paxlovid is that it consists of the antiviral nirmatrelvir given in combination with ritonavir. Ritonavir is an old HIV drug that can interact with most medication and as such, most high-risk patients may well be on a medication that could interact.
Fluvoxamine, an antidepressant pill that is approved for obsessive-compulsive disorder, appears to reduce the inflammatory response. In a randomised trial of 1,497 high-risk COVID outpatients in Brazil, those who tolerated a 10-day course of fluvoxamine suffered about 90% fewer deaths and their need for emergency care fell by 65% compared with patients who were randomly assigned placebo pills.
Budesonide, an inhaled steroid used to prevent asthma symptoms, has shown a modest benefit in a large open-label study in the United Kingdom. This enrolled older non-hospitalised patients with comorbidities such as high blood pressure and diabetes. Those who started to use the inhaler within two weeks of developing COVID symptoms saw an approximately three-day reduction in symptom duration. Mild benefit therefore was noted during the second week of illness.
What about the old COVID drugs, is there any hope?
New research suggests remdesivir could be helpful in COVID outpatients. In a randomised trial published in December in the New England Journal of Medicine, COVID-related hospitalisations and deaths were 87% lower in 279 symptomatic, non-hospitalised patients who received remdesivir compared with 283 in the placebo group. However, logistically, this involves three days of infusions.
What about convalescent plasma?
There are similar logistical hurdles and it is unclear from past research about the utility of convalescent plasma. This is blood collected from donors who have recovered from COVID-19. At the moment, it does not seem to be of any great benefit. However, new research appears to be reviving interest. A not yet peer reviewed preprint paper reveal that in a study of 1181 patients, convalescent plasma cut hospitalisation by 54% when administered within the first eight days of COVID symptoms.
The London General Practice, the leading doctors’ clinic in Harley Street, commends the government on its vaccination programme but would like to see the advent of antiviral therapies introduced into the outpatient setting as soon as possible.
Dr Paul Ettlinger
BM, DRCOG, FRCGP, FRIPH, DOccMed