Key points
- Early diagnosis and treatment might increase the chances of survival from non-keratitis Acanthamoeba infections.
- Recommendations for treatment are based on a small number of cases, and more research is needed to learn how best to treat patients with Acanthamoeba infections.
Treatment options
Although non-keratitis Acanthamoeba infections are often fatal, some patients have survived. Patients with granulomatous amebic encephalitis (GAE), an infection of the brain, have a lower chance of survival compared with those with cutaneous acanthamoebiasis, a skin infection. More research about treating Acanthamoeba infections is needed.
Effective treatment for infections caused by Acanthamoeba has not been established. Current recommendations are based on a small number of Acanthamoeba survivor case reports. The duration of treatment for patients with an Acanthamoeba infection has not been established. In case reports of survivors, duration of treatment is often several months or 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.
Treatment recommendations
The following regimen of medications is recommended for patients with all presentations of non-keratitis Acanthamoeba infections, including GAE, cutaneous acanthamoebiasis, Acanthamoeba rhinosinusitis, and disseminated infections.
| 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 does not cross the normal, intact blood-brain barrier well. Its use constitutes 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 varies based on drug and patient. Consult a clinical pharmacist with dosing questions. | Fluconazole and itraconazole are NOT recommended due to poor in vitro efficacy. |
| Miltefosine (oral)1 | Up to 45 kg body weight: 100 mg daily (i.e., one 50 mg capsule by mouth 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 capsule by mouth with breakfast, lunch, and dinner) |
Miltefosine is now commercially available. Visit impavido.com for more information. |
| Nitroxoline2
|
Contact CDC for information | Nitroxoline is an investigational drug that may be effective for Acanthamoeba infections. It is not FDA-approved in the United States. |
1The 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 could lead to nausea, vomiting, diarrhea, or other side effects. Miltefosine can cause increased serum creatinine, but dosing generally does not need to be adjusted for impaired renal function. Because few data are available about the effective dose for amebic infection, the risk for nephrotoxicity should be balanced against the risk of death from amebic infections.
2Nitroxoline is an investigational drug that may be effective for Acanthamoeba infections. It is not FDA-approved in the United States, but is available as an experimental drug for treatment of free-living ameba infections through CDC's expanded access Investigational New Drug program. The original stock donated to CDC is no longer available for new patients. CDC is working to secure an additional supply. The experience with nitroxoline is too limited to draw conclusions. Contact the CDC Emergency Operations Center at 770-488-7100 for more information.
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