Strongyloides disseminated infection successfully treated with parenteral ivermectin: case report with drug concentration measurements and review of the literature

We report the case of an immunosuppressed patient with Strongyloides disseminated infection who was successfully treated with the veterinary parenteral form of ivermectin. A kidney transplant recipient developed disseminated infection with Strongyloides stercoralis. Because oral treatment with ivermectin was not possible, subcutaneous ivermectin (75 µg/kg/day, then 200 µg/kg/day) was given for 9 days, with clinical improvement and disappearance of all larvae. Serum ivermectin concentrations were between 15.6 ng/mL and 19.7 ng/mL during the 9 days of therapy; however, drug accumulation (plasma levels >40 ng/mL) 48 h after discontinuation of therapy was associated with the development with encephalopathy. We also review all cases of human disseminated Strongyloides infection treated with parenteral ivermectin.