Antibiotics, HIV drugs can inhibit Covid-19: Study

Antibiotic, anti-inflammatory and HIV drugs can inhibit the Sars-CoV-2 virus which causes Covid-19, while anti-malarial medicine is less effective in fighting the disease, a new study has found.

The findings were originally determined in April in Bengaluru but published in Elsevier’s Journal of Molecular Graphics and Modelling in October after peer review. They come at a time when a viable Covid-19 vaccine is not in immediate sight.

Dr C N Prashantha, Assistant Professor of the Department of Biotechnology at Reva University, who is the corresponding author for the study, explained that the objective of the research was to determine which drugs can be used to inhibit the virus’ S2 protein from binding with the ACE2 receptor of human cells, mediating viral cell entry.

The research team said that it studied over 30 commercially available drugs, including eight anti-malarial, 20 HIV-protease inhibitor and several anti-inflammatory drugs besides antibiotics.

“Through our computational model, we discovered that antimalarial drugs such as chloroquine, hydroxychloroquine (HCQ) and artemisinin have poor affinity to the virus spike protein, and that they are not effective against the virus. However, very good effects were observed when HIV protease-inhibitors were tested,” Dr Prashantha said.

Among the HIV drugs showing the strongest effect were lopinavir, cobicistat, ritonavir and darunavir. “Among the antibiotics, erythromycin and spiramycin molecules have good affinity,” he added.

Three anti-inflammatory drugs also showed efficacy against the virus: thalidomide, ruxolitinib and baricitinib. Interestingly, a March 2020 letter to the journal Lancet claimed that anti-inflammatory drugs (especially ibuprofen and thiazolidinediones) can aggravate Covid infection because they inhibit the ACE2 receptor. The existing scientific literature, however, says this has not been clinically observed.

Dr Prashantha defended the move to test the anti-inflammatory drugs, saying the intention was to give medical professionals access to a wider option of viable drugs to use against Covid-19.

Clinical studies needed

Dr Anoop Amarnath, a member of the State Covid Task Force and unconnected to the study, explained that insilico studies (where biological experiments are simulated) are fairly good screening methodologies for identifying potential treatment candidate molecules. However, he added that further studies are needed.

“Although pharmacokinetics may be simulated, pharmacodynamic properties, especially invivo (within the body) may be varied and hence the need for robust clinical trials before concluding the clinical efficacy,” said Dr Amarnath, who heads the Clinical Research and Scientific Review Board at Manipal Hospital.

Dr Prashantha agreed, saying that the computational study was only a basis for a more robust clinical study.

According to Dr Amarnath, three of the drugs examined in the study have been used clinically to treat Covid-19: HCQ, ritonavir and lopinavir.