Repurposing of drugs for Covid-19: a systematic review and meta-analysis.

The aim of this systematic review is to evaluate the data currently available regarding the repurposing of different drugs for Covid-19 treatment. Participants with suspected or diagnosed Covid-19 will be included. The interventions being considered are drugs being repurposed, and comparators will include standard of care treatment or placebo.We searched Ovid-MEDLINE, EMBASE, Cochrane library, clinical trial registration site in the UK(NIHR), Europe (clinicaltrialsregister.eu), US (ClinicalTrials.gov) and internationally (isrctn.com), and reviewed the reference lists of articles for eligible articles published up to April 22, 2020. All studies in English that evaluated the efficacy of the listed drugs were included. Cochrane RoB 2.0 and ROBINS-I tool were used to assess study quality. This systematic review adheres to the PRISMA guidelines. The protocol is available at PROSPERO (CRD42020180915).From 708 identified studies or clinical trials, 16 studies and 16 case reports met our eligibility criteria. Of these, 6 were randomized controlled trials (763 patients), 7 cohort studies (321 patients) and 3 case series (191 patients). Chloroquine (CQ) had a 100% discharge rate compared to 50% with lopinavir-ritonavir at day 14, however a trial has recommended against a high dosage due to cardiotoxic events. Hydroxychloroquine (HCQ) has shown no significant improvement in negative seroconversion rate which is also seen in our meta-analysis (p=0.68). Adverse events with HCQ have a significant difference compared to the control group (p=0.001). Lopinavir-ritonavir has shown no improvement in time to clinical improvement which is seen in our meta-analyses (p=0.1). Remdesivir has shown no significant improvement in time to clinical improvement but this trial had insufficient power.Due to the paucity in evidence, it is difficult to establish the efficacy of these drugs in the treatment of Covid-19 as currently there is no significant clinical effectiveness of the repurposed drugs. Further large clinical trials are required to achieve more reliable findings. A risk-benefit analysis is required on an individual basis to weigh out the potential improvement in clinical outcome and viral load reduction compared to the risks of the adverse events.