1.     INTRODUCTION
As per the U.S Department of Health and Human Services and U.S FDA, immunosuppressant drugs can cause susceptibility to viruses leading to infection with increase in morbidity of the disease. It can cause severe risk of illness from COVID-19 due to a weakened immune system. Immunosuppressant drugs like Etanercept, Mycophenolate mofetil, Sirolimus, Cyclosporine and Rituximab can weaken the immune system and make patients vulnerable to COVID-19 [1-2]. These drugs suppress the body’s immune response to prevent organ rejection during solid organ transplantation and  could be used to treat autoimmune disorder, Crohn’s disease, Rheumatoid arthritis, Psoriasis, Nephrotic syndrome, and lung disease like lymphangioleiomyomatosis. Immunosuppressants can lower the body's defence mechanism to ward off viruses and infections. However, it is recommended not to stop immunosuppressants without consulting respective healthcare providers as it can lead to flare up of the underlying disease or treatment process. Immunosuppressants can be stopped temporarily if someone is not feeling well and develops fever, sore throat, runny nose or any other respiratory symptoms. It can be continued again once a person feels better [3-5].
COVID-19 precautionary measures are advised for immunocompromised patients suffering from underlying medical conditions like cancer, HIV, genetic immune deficiencies, multiple sclerosis, lupus, rheumatoid arthritis. Patients undergoing treatment procedures like bone marrow transplant, solid organ transplant, stem cells transplant are also advised to follow the same guidelines as advised by the U.S CDC. Also, patients taking immunosuppressant drugs like etanercept, mycophenolate mofetil, sirolimus, cyclosporine and rituximab irrespective of their medical condition should maintain enhanced COVID-19 precautionary measures like refrain from non-essential travel, avoid touching eyes and mouth with unwashed hands, wear N95 respirator or cloth mask, maintain social distancing of at least 6 feet and stay at home as much as possible. Moreover, they should disinfect household objects touched frequently and avoid sharing personal items with others, wash hands with soap and water for at least 20 seconds or use hand sanitizer with at least 60% alcohol content. In this study, we discuss the pharmaceutical properties of immunosuppressant drugs, associated risk factors with COVID-19, contraindications, adverse reactions and drug-drug interactions [6-9].
2. METHODOLOGY
In this review, online literature search was done on Medline, PubMed and google scholar databases for studies on hospital-based management/ treatment of COVID-19 globally and relevant studies were identified. This review includes various immunosuppressant drugs therapy and their effect on COVID-19 patients . The drugs such as Etanercept, Mycophenolate mofetil, Sirolimus, Cyclosporine and Rituximab are described in detail. The review describes the drug pharmaceutical properties, mechanism of action, risk associated with the drug therapy for COVID-19, contraindications, drug-drug interactions, side effects and risks.