Key points
- Early diagnosis and treatment might increase the chances of survival from a Balamuthia infection.
- More research is needed to learn how best to treat patients with Balamuthia infections.
Treatment options
Clinicians
Balamuthia can cause rare but serious illnesses. They include a nearly always fatal brain infection called granulomatous amebic encephalitis, or GAE. Even when patients with GAE are treated with medications, most do not survive. Much more information is needed in treating patients with GAE due to Balamuthia.
Treatment recommendations
Effective treatment for infections caused by Balamuthia mandrillaris has not been established. The recommendations are based on a small number of Balamuthia survivor case reports.
The duration of treatment for people with a Balamuthia infection also has not been established. In case reports of survivors, duration of treatment has ranged from several weeks to several months, or even years. The decision to stop treatment should be made on a case-by-case basis and include consideration of the patient's clinical status and review of laboratory and radiographic findings.
| Drug | Dose | Notes |
|---|---|---|
| Pentamidine (IV) | 4 mg/kg given once per day | Although pentamidine has been used successfully in combination with the drugs listed below, pentamidine is very toxic and doesn’t cross the normal, intact blood-brain barrier well. Its use must be a clinical decision. |
| Sulfadiazine (oral) | 1.5 g every 6 hours in adults; 200 mg/kg/day in 4–6 doses in pediatric patients (maximum 6 g/day) | |
| Flucytosine (oral) | 37.5 mg/kg every 6 hours (maximum 150 mg/kg/day) | |
| A mold-active azole (e.g., voriconazole, posaconazole, or isavuconazole) | Dosing will vary based on drug and patient. Consult a clinical pharmacist with dosing questions. | Fluconazole and itraconazole are NOT recommended due to poor in vitro efficacy. |
| Azithromycin (oral or IV) | 20 mg/kg/day in 1 dose (max 500 mg/day) in pediatric patients; 500 mg/day in 1 dose for adults | |
| Clarithromycin (oral, alternative to azithromycin) | 14 mg/kg/day in 2 doses (max 2 g/day) | |
| Miltefosine (oral)a | Up to 45 kg body weight: 100 mg daily (i.e., one 50 mg cap po with breakfast and dinner)
For pediatric cases, 2.5 mg/kg/day up to 100 mg daily 45 kg body weight and higher: 150 mg daily (i.e., one 50 mg cap po with breakfast, lunch, and dinner) |
Miltefosine is now commercially available. Visit impavido.com for more information. |
aThe standard miltefosine dosing recommended for the treatment of leishmaniasis is presented in the table. The oral preparation is the only formulation available. A higher dose would lead to increased nausea, vomiting, or diarrhea. Miltefosine is mildly nephrotoxic but is not cleared by the kidneys, so dosing does not need to be adjusted for patients with impaired renal function. Because little data are available about the effective dose for amebic infection, the risk for nephrotoxicity should be balanced with the risk of death from GAE or disseminated disease.
Although Balamuthia GAE is often fatal, there are several recorded cases of Balamuthia infection in the United States in which the patient survived after long-term treatment with multiple drugs. Survivors have also been reported in other countries. Some U.S. survivors had excisional biopsies of one of their multiple brain lesions. At least one survivor had an accompanying cutaneous lesion. Early diagnosis and treatment might increase the chances for survival.