Coronavirus: Drugs that have been used for COVID-19 treatment and their efficacy (and risks)

Apart from prevention measures like wearing masks and keeping oneself sanitized, drugs and medicines play an important role in controlling the spread of COVID-19 infection. Vaccination is another effective way against the spread of the infection but its availability is limited. "Vaccination is having a substantial impact on case numbers and hospitalizations in a number of high-income countries, but limitations in global access to vaccines mean that many populations remain vulnerable," the World Health Organisation (WHO) says. " Even in vaccinated individuals, uncertainties remain about the duration of protection and efficacy of current vaccines – and the efficacy of existing treatments for COVID-19 – against emerging SARS-CoV-2 variants," it adds.

Drugs which are commonly used for COVID-19 treatment are listed below along with what experts and reports suggest on them:

In late 2020, Baricitinib was given emergency use authorization by the the U.S. Food and Drug Administration as therapy in combination with remdesivir for severe COVID-19. On January 14, 2022, the WHO approved Barcitinib as a drug for treatment of COVID-19. WHO strongly recommends this to be given to patients with severe or critical COVID-19 with corticosteroids. It is part of a class of drugs called Janus kinase (JAK) inhibitors that suppress the overstimulation of the immune system. "In patients with severe or critical illness, baricitinib probably reduces mortality and duration of mechanical ventilation, and reduces hospital length of stay. It probably results in little or no increase in serious adverse events," WHO GDG says.

These are highly recommended for COVID treatment for patients with severe or critical COVID-19. However, for those with non-severe infections, it is not recommended. There are research evidences on the use of systemic corticosteroids for treatment of acute asthma symptoms though few research studies suggest that while corticosteroids are relatively inexpensive their long-term use is known to be associated with certain toxicities. Observations have revealed an increased risk of bone fracture, infection, and gastrointestinal bleeding.

Coronavirus: The long term COVID-19 symptom no one is talking about

This is the first oral, direct-acting antiviral shown to be highly effective at reducing nasopharyngeal coronavirus infectious virus and viral RNA. As on October 27, 2021, WHO and Unitaid signed a voluntary licensing agreement by the Medicines Patent Pool (MPP) and MSD to facilitate affordable access to molnupiravir. This drug cuts down the risk of hospitalisation in COVID-19 patients by 30%. However, this drug is not a part of national treatment protocol prescribed by the Indian government. Last week, ICMR had pointed out serious concerns with the use of this drug in children, pregnant and lactating women. ICMR hd said it causes teratogenicity, mutagenicity, and it can also cause cartilage damage and can also be damaging to muscles.

WHO has recommended this for treating mild or moderate COVID-19 in patients who are at high risk of hospitalization. This monoclonal antibody drug has been recommended for patients who are older, immunocompromised, having underlying conditions like diabetes, hypertension, and obesity, and those unvaccinated. A research study published in the New England Journal of Medicine corroborates WHO recommendations and holds in its study that among high-risk patients with mild-to-moderate Covid-19, sotrovimab reduced the risk of disease progression. "In patients with non-severe illness, sotrovimab probably reduces hospitalization, with little or no impact on infusion reactions, with no data on time to clinical improvement. Sotrovimab probably has little or no impact on mortality and on mechanical ventilation," the WHO says.

These IL-6 receptor blockers are strongly recommended for patients with severe or critical COVID-19. These can be used as an alternative to baricitinib. "IL-6 receptor blockers reduce mortality and need for mechanical ventilation based on high certainty evidence. Low certainty evidence suggests they may also reduce duration of mechanical ventilation and hospitalization," WHO says.

A research study titled "Tocilizumab and sarilumab alone or in combination with corticosteroids for COVID-19: A systematic review and network meta-analysis" published in medRxiv in July 2021 says that that IL-6 receptor blockers like Tocilizumab or sarilumab when added to standard care that includes corticosteroids, in patients with severe or critical COVID-19, probably reduce mortality.

WHO had recommended it in September 2021 to treat COVID-19 patients. In its latest report, it has recommended Sotrovimab as an alternative to this on the basis that on studies on the effectiveness of monoclonal antibodies against Omicron early laboratory studies show that sotrovimab retains its activity. However, it recommends not giving sotrovimab and casirivimab-imdevimab together.

WHO has granted conditional recommendation to the use of this drug. As per the WHO report, these two drugs should only be recommended for patients with severe or critical COVID-19 if neither baricitinib nor IL-6 receptor blockers (tocilizumab or sarilumab) are available. "The effects of ruxolitinib or tofacitinib on mortality, need for mechanical ventilation and hospital length of stay remain uncertain. Tofacinib may increase adverse events leading to drug discontinuation," it has said.

Paxlovid has shown to reduce the chances of hospitalisation or death from Covid-19 in high-risk patients by 89%. As per the Europeans Medicines Agency, the side effects of using Paxlovid are dysgeusia (taste disturbance), diarrhoea and vomiting. " The medicine, which is not yet authorised in the EU, can be used to treat adults with COVID-19 who do not require supplemental oxygen and who are at increased risk of progressing to severe disease," the EMA had said on December 16. "Paxlovid must not be used with certain other medicines, either because due to its action it may lead to harmful increases in their blood levels, or because conversely some medicines may reduce the activity of Paxlovid itself," it has added.

This commonly prescribed antibiotic is often prescribed as a treatment for COVID-19. In a research study published in medRxiv, the antiviral, anti-inflammatory, immunomodulatory benefits of Azithromycin drug with Zinc make this drugs combination a good candidate therapy to treat flu-like-COVID-19 and atypical pneumoniae. Azithromycin has demonstrated antiviral activity against Zika virus and rhinoviruses. However, in its latest therapeutics guidelines, the WHO has not mentioned it as a treatment for COVID-19.

As per the GDG observation, there was low certainty evidence that lopinavir/ritonavir may increase the risk of diarrhea and nausea and vomiting, a finding consistent with the indirect evidence evaluating its use in patients with HIV. Diarrhea and vomiting may up the risk of hypovolaemia, hypotension and acute kidney injury, this may worsen the condition of the patient when there are no health care resources nearby.

Ivermectin has been approved to treat infections caused by some parasitic worms and head lice and skin conditions like rosacea in human beings. The clinical data available right now doesn't give a green signal for the use of this drug against COVID-19. WHO is strongly against the use of Ivermectin for the treatment of COVID-19. It has only recommended it for clinical trials. "A recommendation to only use a drug in the setting of clinical trials is appropriate when there is very low certainty evidence and future research has a large potential for reducing uncertainty about the effects of the intervention and for doing so at reasonable cost," it says.

This anti-malaria drug was known for certain time as a cure for COVID-19. However, experts recommend against its use for coronavirus induced infection. WHO strongly recommends against the use of Hydroxychloroquine for treatment of COVID-19 and says it does not reduce mortality or mechanical ventilation and may not reduce duration of hospitalization.