Treatment of Progressive Multifocal Leukoencephalopathy With Mirtazapine
Background and ObjectivesProgressive multifocal leukoencephalopathy (PML) is a rare, JC virus mediated, demyelinating disease with a high mortality rate. As no recommended treatment exists, mirtazapine, a potential blocker of virus entry into cells, has been empirically used.MethodsWe analysed existing data on mirtazapine's efficacy to treat PML by systematically reviewing the literature since 2005, when it was first used.ResultsSearches in PubMed, EBSCO, SCOPUS and Google Scholar between January 2005 and December 2015, identified five cohort studies and 74 case reports. No statistically significant effect of mirtazapine on PML outcome was observed in the cohort studies. From studying the case reports, mortality rate for PML was associated with the underlying circumstances, such as an older age, the use of an immunosuppressant, or PML occurring in patients with a haematological malignancy or a transplant.ConclusionsExcept for natalizumab associated PML, we did not highlight any potential benefit of mirtazapine on disease outcomes. Further interventional studies are needed to confirm that 5 HT2AR inhibition is relevant to treat PML.
Clinical Drug Investigation