Mirtazapine Use in Human Immunodeficiency Virus–Infected Patients With Progressive Multifocal Leukoencephalopathy

BACKGROUND: An efficacious treatment is needed for human immunodeficiency virus (HIV)-infected and uninfected patients with progressive multifocal leukoencephalopathy (PML). OBJECTIVE: To report clinical and magnetic resonance imaging changes in response to mirtazapine treatment in HIV-positive patients with PML. DESIGN: Case series. SETTING: Outpatient neurology clinic. PATIENTS: Four HIV-positive patients with PML. INTERVENTIONS: Mirtazapine use, 15 mg nightly. MAIN OUTCOME MEASURES: Neurologic examinations and cranial magnetic resonance imaging. RESULTS: Three patients demonstrated objective clinical improvement, and 1 patient showed improvement on magnetic resonance imaging. The patient who experienced the most significant clinical improvement was the patient who received mirtazapine therapy closest to PML symptom onset. Mirtazapine use was safe and well tolerated. CONCLUSION: Mirtazapine use may offer some benefit as treatment or prophylaxis for PML in patients with HIV infection.