Lopinavir/Ritonavir, a fixed dose combination antiretroviral sold under the brand name of Kaletra, has been approved by the Central Drugs Standard Control Organization (CDSCO), for restricted public health use among the symptomatic Covid-19 patients, as per an ‘ahead of print’ article in the special edition of the Indian Journal of Medical Research brought out by the Indian Council of Medical Research.
Hospitalised adult patients with laboratory confirmed SARS CoV-2 infection can give written informed consent to receive the treatment for 14 days if they meet any of the following criteria: a) respiratory distress with respiratory rate greater than equal to 22/min or blood-oxygen levels (oxygenated haemoglobin as a percentage of total haemoglobin) of <94%; b) lung parenchymal infiltrates (substance denser than air, such as pus, blood, protein, etc, present in the portion of the lung involved in gas transfer) confirmed by X-ray; hypotension defined as systolic blood pressure <90 mmHg or need for vasopressor/inotropic medication; new-onset organ dysfunction, including kidney failure; and high-risk groups–age >60 yr, diabetes mellitus, renal failure, chronic lung disease and immuno compromised persons.
The patients administered this treatment protocol will be monitored to document clinical (length of hospital stay, mortality at 14, 28 and 90 days), laboratory (presence of viral RNA in serial throat swab samples) and safety (side-effects, including serious ones) outcomes. If found useful in managing SARS CoV-2 infections, further evaluation using randomised control trial design is warranted, the authors of the paper, Tarun Bhatnagar, Manoj V Murhekar, Manish Soneja, Nivedita Gupta, Sidhartha Giri, Naveet Wig and Raman Gangakhedkar, all ICMR and AIIMS researchers, write.
The decision to test the Lopinavir/Ritonavir combination that has been used over 15 years to treat HIV was taken on the basis of some historical control studies and case reports showing efffectiveness against SARS and MERS coronavirus infections, as also the ‘docking’ (a molecule latching on to a protein, in this case, likely the surface protein of the pathogen) tests that ICMR has conducted. In one control study cited by the authors in the article, the lopinavir/ritonavir combination, given along with ribavirin to SARS patients, reported a much lower rate of death compared to the control group that received only ribavirin (2.4% versus 28.8%) at day 21 of the onset of symptoms.
While the ICMR-AIIMS researchers recommend a lopinavir/ritonavir dose of two tablets (200mg/50mg) every 12 hours for 14 days or for seven days after a patient turns asymptomatic, whichever is earlier (400 mg/100 mg in 5 ml suspension administered via a nasogastric tube for patients unable to swallow pills), they have cautioned against usage in cases where the patient suffers from liver ailments, where the patient requires medicines, including a key TB drug, that can’t be prescribed together with the lopinavir/ritonavir combination and HIV patients receiving treatment protocols where lopinavir/ritonavir can’t act as substitutes.
However, Chinese medical researchers (Bin Cao et al), publishing in the New England Journal of Medicine on March 18, have concluded that lopinavir/ritonavir didn’t deliver any observed benefits above the standard care protocol in a randomised, controlled trial of 199 SARS CoV-2 infected patients. They used a treatment protocol involving 400 mg/100 mg administered twice daily for 14 days in addition to standard care for the treatment group of 99, while the control group received standard care alone. Mortality at 28 days was similar between the two groups as well as detectable viral RNA at various points of time.