COVID19 Fact Sheet #5 Drug Treatment Options
COVID19 Fact Sheet #5: Drug Treatment Options
These fact sheets will provide data about characteristics, diagnosis, management, and prevention of COVID19. Fact sheet #5 will present known facts about drug options actually researched for the treatment of the coronavirus disease (COVID19).
Unfortunately, according to the World Health Organization (WHO), the Centers for Disease Control and Prevention (CDC), and the U.S. Food and Drug Administration (FDA), there are currently no medications or vaccines proven to be effective for the treatment or prevention of COVID19.
COVID19 Chinese Guideline
In the absence of an established treatment regimen, the Chinese authorities issued a COVID19 guideline in February 2020 recommending the use of lopinavir; ritonavir (drugs against HIV), in combination with inhalations of alfa-interferon, a substance regulating the immune system used in hepatitis or leukaemia.
It appears that antiviral medications are less useful in young, healthy patients with mild symptoms and no other medical conditions. However, this treatment offered to older patients or patients with underlying conditions and serious symptoms.
COVID19 Potential future treatment options
Chloroquine is a cheap, widely available anti-malaria drug that has been routinely used since 1945. It can be safely taken by pregnant women and children. Studies suggest, that the drug might effective against the coronavirus, at least in the laboratory, and a small French study in 24 patients from this week, suggested that chloroquine could quicken recovery. (One in four patients who received the drug tested positive for the virus after six days, compared with nine out of ten of those who did not receive it. Chloroquine and a related drug, hydroxychloroquine, are tested in an international clinical trial, announced by the World Health Organization (WHO).
As interferon alpha, used according to the Chinese guidelines together with lopinavir and ritonavir, interferon beta forms a part of the human immune system, particularly as the lung’s natural defense system against viruses. It was originally intended chronic obstructive pulmonary disorder, or COPD.
It was identified in February by the WHO as the only therapy in phase-2 trials that can be inhaled, meaning patients can administer it themselves. The UK biotech firm Synairgen has been given fast-track approval to trial the drug in Covid19 suffering patients.
Remdesivir (GS-5734), an investigational substance
Remdesivir was originally developed as a treatment for Ebola treatment, but it worked in the laboratory against coronaviruses causing SARS in 2002 and MERS in 2013, that are more lethal but less transmissible. The drug shuts off the virus’s ability to multiply inside cells.
Remdesivir has been administered to several hundred patients with confirmed, severe COVID19 in the United States, Europe, and Japan through Expanded Access or Compassionate Use programs. Trial results about this substance are expected by April 2020.
Sofosbuvir in combination with ribavirin:
Data from a molecular experiment suggest a possible efficacy of sofosbuvir and ribavirin in treating the COVID19 infection. Further data will continue to emerge regarding antiviral therapy for SARS-CoV-2 as clinical data are reported.
Favipiravir, developed by a subsidiary of Fujifilm against new strains of influenza, could more than halve the time that SARS-CoV-2 would test positive in patients with COVID19. A Chinese trial in 340 people showed that the virus tended to be cleared in four days as compared to 11 days in patients who went without faviparivir. Chest scans revealed likewise less damage in those who took the drug. But the substance, also known as Avigan®, may need to be given before virus levels peak in the body. It did not appear to work as well in severely ill patients, after the virus had had more time to replicate.
The antiviral medicines from Chinese guideline mentioned above, lopinavir and ritonavir, are normally used to treat HIV (combined into one drug called Kaletra®). Initially they held promise as a potential Covid19 treatment. However, the first major studies of 200 seriously ill patients from China did not find any benefit. It is possible though, that the drug could be effective if given earlier on, or to less severely ill patients, or in combination with corticosteroids. (Of note, the WHO currently recommends against routine use of corticosteroids in patients with SARS-CoV-2, as available data suggest corticosteroids are associated with no survival benefit and possible harm.) The WHO has included Kaletra in a major multi-country trial launched this week.
During the Spanish flu pandemic of 1918 doctors have treated some critically ill patients with the blood plasma of recovered patients. The logic is that recovered patients would build antibodies against the pathogen. Downsides include the risk of transmitting other diseases and that the relevant antibodies are only present in small amounts. The treatment is also hard to scale to the needs of widespread use.
Among others, the US company Regeneron, is working on the hi-tech equivalent of serum therapy. Regeneron hopes to be a few weeks away from identifying two powerful antibodies against Covid19. The antibodies could then be manufactured synthetically and turn into a drug, ready human trials in the summer. If successful, an antibody therapy could help as both, a treatment and to protect health workers or other high-risk groups.
Studies of vaccines have begun. The hope is that we will have a coronavirus vaccine in 12-18 months, but for that to happen we may have to rely on untested techniques – and that comes with its own risks.
Tim Smith, PharmD, BCPS and Tony Prosser, PharmD: COVID19 Drug Therapy – Potential Options (https://www.elsevier.com/__data/assets/pdf_file/0007/988648/COVID19-Drug-Therapy_Mar-2020.pdf )