Background and importance Gastrointestinal complications, including small bowel obstruction and paralytic ileus, are associated with Strongyloides stercoralis hyperinfection syndrome, decreasing oral bioavailability. Ivermectin is the firstline agent for the treatment of strongyloidiasis as well as S stercoralis hyperinfection. In Europe, ivermectin is available in oral and parenteral formulations but the European Medicines Agency (EMA) has approved only the oral formulation for human use.
Aim and objectives The aim of the study was to describe alternatives to oral ivermectin when enteral absorption is compromised, regarding a recent case in our hospital.
Material and methods A bibliographic search was made using databases such as MEDLINE (Pubmed) and Micromedex. A specific search for official regulatory documents concerning human and veterinary medical products, from the websites of the EMA, was carried out. Therapeutic options found were assessed by the multidisciplinary infectious diseases team, including a clinical pharmacist.
Results Rectal and parenteral administration of ivermectin were the two therapeutic alternatives found to the oral route. Subcutaneous ivermectin is approved in Europe for veterinary use; its use in humans may be a therapeutic option but this requires an investigational new drug exemption from the EMA. After approval, subcutaneous ivermectin was started at a dose of 200 µg/kg/day. The rectal route was also assessed. Compounding pharmacists prepared enemas of ivermectin (12 mg/30 mL) from the tablets marketed for human use, which were administered every 12 hours. A progressive decrease in the parasite load was observed. S stercoralis was no longer detected in stools after 14 days of treatment, and on sputum gram stain after 25 days. The patient continued on therapy until a second negative sputum on day 33. Despite the resolution of the S stercoralis infection, the patient died due to multiple complications, including sepsis caused by translocation through the intestinal mucosa of gram negative bacteria into the bloodstream together with the larvae.
Conclusion and relevance The lack of treatment alternatives to oral ivermectin implies the use of off-label therapies. Subcutaneous ivermectin, available for veterinary use, and rectal ivermectin, compounded from marketed tablets, could be valid options when oral bioavailability is decreased. Further research is needed to fill the gap of ivermectin administration in patients with compromised enteral absorption.
Conflict of interest No conflict of interest
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