Abstract. Two cases of Strongyloides hyperinfection are presented. Ivermectin was initially administered orally and per rectum pending the availability of subcutaneous (SC) preparations. In neither case did rectal suppositories of ivermectin achieve clinically meaningful serum values. Clinicians should use SC preparations of ivermectin as early as possible in Strongyloides hyperinfection and dissemination.
CASE 1A 38-year-old Nigerian-born female with no prior medical history presented with worsening nausea and vomiting over a 6-week period. One year prior admission she had traveled to Nigeria for 1 month. Two months before admission she was referred to a gastroenterologist for dyspepsia and underwent upper endoscopy with a small bowel biopsy. At the time of her presentation to hospital, endoscopic biopsy results showed filariform larvae of Strongyloides stercoralis. On admission she was ill appearing, afebrile, with a blood pressure of 90/ 50 mmHg, heart rate of 115 beats/min, and normal oxygen saturations. Her examination was unremarkable apart from a tender epigastrium and diminished bowel sounds.Blood examination revealed a normal complete blood count, creatinine, and liver function tests. Computed tomography (CT) of her abdomen with contrast demonstrated a thickened proximal small bowel wall and evidence of ileus. Strongyloides hyperinfection syndrome was suspected, and she was empirically treated with crystalloid resuscitation and albendazole (400 mg PO BID) while an urgent request for ivermectin was made to Health Canada (ivermectin is a special access drug in Canada available only with the authorization of the Health Protection Branch). In addition, intravenous ceftriaxone and metronidazole were administered for presumed gram-negative sepsis. The patient was unable to tolerate oral albendazole because of intractable nausea and vomiting, so albendazole was administered via nasogastric (NG) tube although there was concern regarding poor absorption given her ileus and persistent vomiting. Pending the availability of subcutaneous (SC) ivermectin, we had a compounding pharmacy prepare oral ivermectin into rectal suppositories; we administered these in the evening on her first and second hospital day (200 μg/kg, totaling 15 mg per rectum (PR). Her persistent ileus prompted the General Surgery service to perform an urgent laparotomy on her second hospital day. She was found to have a dilated proximal small bowel, what appeared to be a fecal bezoar as a result of the ileus that was milked distally. She required norepinephrine for blood pressure control during the operation and for 6 hours immediately after. She was extubated shortly after her laparotomy and was able to tolerate oral medications the following day at which point she was given oral ivermectin. Table 1 shows her medication schedule and microbiology results during and after her hospital stay. Serum ivermectin levels were measured on hospital day 2, 3, and 8 as per the protocol described previously in a study. 1 PR ivermectin did not achieve clinicall...