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
Clinicians
Although non-keratitis Acanthamoeba infections are often fatal, there have been some survivors. Patients with granulomatous amebic encephalitis (GAE), an infection of the brain, have a lower chance of survival compared to 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. The following recommendations are based on a small number of Acanthamoeba survivor case reports. The duration of treatment for people with an Acanthamoeba infection also 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 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 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. |
| 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.