Subcutaneous Ivermectin Use in Strongyloides Hyperinfection

Introduction: Strongyloidiasis stercoralis can lead to poor outcomes in immunocompromised transplant patients. The larvae penetrate the skin and travel to the intestine. They mature and produce eggs. These eggs mature into larvae and penetrate through the intestinal wall to enter the blood stream. GI issues may prevent enteral absorption of anthelminthics. There are no parenteral anthelminthics licensed for use in humans by the Federal Drug Administration (FDA). Here we describe the use of veterinary grade subcutaneous ivermectin in an immunocompromised kidney transplant patient that developed donor derived Strongyloidiasis hyperinfection. Case Description: A 36-year-old female had a deceased donor kidney transplant in October 2024 and presented with abdominal pain, rash, nausea and emesis in December 2024. She required pressor support, intubation and prone positioning. Sputum culture showed helminth infection so oral ivermectin and albendazole were initiated. Due to her prone position and an ileus, there was concern of poor oral absorption of the drugs. Emergency use authorization was given by the FDA for veterinarian subcutaneous ivermectin. She was transitioned to oral ivermectin once her sputum and stool cultures were repeatedly negative. Discussion: Ivermectin is protein bound and has high oral bioavailability, so serum drug levels can be elevated in patients with hypoalbuminemia. Subcutaneous ivermectin gives better systemic response in the setting of GI issues. Reports have shown varied dose and length of use for treatment, with a range in drug levels and no correlation to patient outcome. There are reported successful outcomes with parenteral ivermectin as a treatment in Strongyloides hyperinfection. There remains no standard protocol or drug monitoring guidelines. Further data to provide appropriate dosing and how to monitor drug toxicity levels is needed.