Miltefosine (Impavido)
Miltefosine was added to the formulary with restriction to use by the Infections Disease services. This agent is active against the pathogens outlined below and was added primarily to provide the ability to rapidly treat free-living amebic encephalitis, a highly fatal condition. All use must be approved by the Infectious Disease service.
- Leishmaniasis: Miltefosine (MLT) is FDA approved for the visceral leishmaniasis (Leishmania donovani), cutaneous leishmaniasis (Leishmania braziliensis, guyanensis, panamensis), and mucosal leishmaniasis (Leishmania braziliensis) in adult patients (≥12 years) weighing ≥30kg. Information on MLT for use in leishmaniasis is readily available in tertiary references and in guidelines (The Infectious Disease Society of America’s Guidelines on Leishmania).
- Free-living amebae: MLT has also been used on a case-by-case basis for treatment of free-living amoebas (FLA). Literature on the efficacy of miltefosine for use in FLA infections is scarce. Regardless, the CDC notes that miltefosine could be used for the treatment of Acanthamoeba, Balamuthis mandrillaris, and Naegleria fowleri infections.
Safety
Miltefosine has several contraindications for use; these include pregnancy, Sjogren-Larsson-Syndrome, and hypersensitivity to it or its components. Miltefosine has a black box warning for embryo-fetal toxicity. Gastrointestinal associated side effects are the most common (i.e., nausea, vomiting, diarrhea). These GI side effects can lead to volume depletion and decreased absorption of oral contraceptive agents.
Cost
This medication very expensive (>$15,000 per bottle) but is available through an Orphan Drugs on Site Program (consignment-like program).