With the increasing number of cases and deaths reported from the novel China Coronavirus infection, the Chinese investigators are desperately searching for a cure. Treatment of the novel Coronavirus infection is thought to be more or less the same as the other Coronaviruses (SARS and MERS). Chinese researchers have been testing a variety of antiviral drugs to find a cure for the novel Coronavirus infection. The Shanghai Institute of Materia Medica under the Chinese Academy of Sciences and ShanghaiTech University tested up to 30 drugs to find drugs that may effectively treat the novel Coronavirus infection [Ref].

Some of the important drugs included:

• anti-HIV drugs including:

  • Indinavir,
  • Saquinavir,
  • Lopinavir and
  • Carfilzomib (used in the treatment of relapsed multiple myeloma)

• Drugs that treat the respiratory syncytial virus infections

• Drugs to treat Schizophrenia

• Immunosuppressants, and 

• Chinese herbal medicines

  • Polygonum cuspidatum.

Which drugs have been found effective in the treatment of Covid-19 infections?

until now, only three drugs have been found to possess a fairly good inhibitory effect at the cellular level. These drugs include:

• Remdesivir,
• Chloroquine (Nivaquine, Resochin), and
• Ritonavir

Chloroquine was the first drug that was used as an effective treatment for malaria infection. It was discovered in China and the tree from which it was derived was used over years for medicinal purposes. Over time, its use has declined because of the emergence of chloroquine-resistant organisms. It penetrates most tissues very well and is active against all the blood stages of malaria infection. It is also used as a once-weekly medicine for the prevention of malaria in travelers visiting the endemic areas and in the treatment of extra-intestinal amebiasis. Apart from its use as an antimicrobial drug, it has got potent anti-inflammatory effects. It is used in the treatment of autoimmune diseases like Rheumatoid arthritis and SLE (systemic lupus erythematosus). [See Coronavirus Treatment Guidelines & Prevention of Coronavirus infection with antimalarials]

How an antimalarial drug may be effective in the treatment of the novel Coronavirus infection?

Chloroquine binds to the DNA and RNA polymerase and inhibits it. It interferes with nucleoprotein synthesis and causes cell damage. It also alters the cellular PH and acid-base balance causing an inhibitory effect on the organism's growth and replication. It also inhibits autophagy. Autophagy is a transport pathway that maintains cellular homeostasis by sequestering cellular structures and unwanted proteins.

Chloroquine for the treatment of Viral infections:

Chloroquine was also studied in patients who got infected with the Chikungunya virus. The drug was effective in the non-human primate model but it enhanced chikungunya virus replication and delayed cellular and humoral responses [Ref]. Chloroquine was also studied in Zika virus infection and found to partially reverse the morphological changes induced by Zika virus infection in mice [Ref]. The antimalarial drug, chloroquine, was also found to be effective in the treatment of the SARS and MERS coronavirus infections. Other viruses that require an acidic intracellular PH include the Filoviruses. Ebola and Marburg viruses are the two important viruses among the Filoviruses. The author of one study concluded that Chloroquine could be used to treat and prevent filoviral infections like Ebola and Marburg and other viral infections requiring an acidic PH for infectivity.

In Conclusion,

Chloroquine is commonly used to treat malaria, however, because of impairing the cellular acid-base balance, it may inhibit the cellular replication of viral infections such as the Wuhan novel Coronavirus infection. Antimalarials (chloroquine and hydroxychloroquine) prevent COVID-19 pneumonia and may limit the symptoms of coronavirus to flu and upper respiratory tract symptoms.