Middle East respiratory syndrome coronavirus (MERS-CoV) has been reported to have a high case-fatality rate. Currently, there is no specific therapy or vaccine with proven effectiveness for MERS-CoV infections.1
A recent systematic review, which included 19 studies with different study designs, looked into possible treatment options for MERS-CoV examining the main outcomes of mortality and morbidity rates and the reported adverse events. The review summarized the therapeutic options for the management of novel coronavirus infection based on previous reports of a related coronavirus called Severe Acute Respiratory Syndrome “SARS”.1 Key interventions include: ribavirin with and without corticosteroids, interferon-alfa with corticosteroids, ribavirin with lopinavir and ritonavir, plus convalescent plasma which may improve outcomes in patients but the data are not conclusive.2
Ribavirin was the most commonly used agent in patients with no other comorbidities. The dose used was 2000 mg as a loading dose then 1200mg every 8 hours for 4 days, then 600mg every 8 hours for 4-6 days.1 It was concluded that ribavirin may have a beneficial role in treating MERS-CoV. In addition, there are significant improvements in clinical outcomes and death rates reduction after adding lopinavir 400 mg to the ribavirin 100mg regimen.1 Furthermore, time of initiating antiviral therapy (time zero) is an important factor in treatment success as failure to therapy has been reported when therapy was delayed.
Other treatment options include steroids therapy. However, there was no mortality benefit reported from using steroids, and on the contrary, there was some opposing evidence for their beneficial role, due to both acute and long-term harms including delayed viral clearing. Therefore, corticosteroid use for MERS-CoV is not recommended outside of an appropriately planned evaluation of effectiveness, except for those where other proven clinical benefits may outweigh harms.2
The only included randomized control trial (RCT) evaluated interferon-1 in a dose of 1.5mcg/kg once per week compared to ribavirin. There was no advantage of ribavirin over interferon. Observational studies comparing interferon-1a with untreated controls showed that interferon led to improvements in clinical and laboratory parameters. However, there was no standard regimen used and adverse events were not well documented. In addition, pegylated interferon alfa (Peg IFN-a) was 50-100 times more effective in vitro for MERS-CoV than SARS-CoV.
Other treatment options include the use of convalescent plasma with the dose of 300–500 mL of full plasma with a rate of 2mL/min for one time in day 2 of ICU admission.2 Cross-reactive antibodies may be present in convalescent plasma from SARS patients against other beta-coronavirus and may be associated with a better outcome of reduced mortality, and shorter hospital stay.2
In conclusion, there is clearly an urgent need for a novel effective antiviral therapy for this emerging global threat. Caution shall be exercised when interpreting the finding of this review due to the high heterogeneity of the reviewed studies in terms of the wide ...