Acute kidney injury related to Cordyceps militaris: A case series

Abstract BackgroundCordyceps sinensis is an ancient traditional Chinese medicine, known as caterpillar fungus, that is one of the most commonly used ingredients to treat people with chronic kidney disease or to facilitate post-kidney transplant health. Unfortunately, due to unavailability and heavy metal contamination, Cordyceps militaris has been substituted instead and incorporated into over 400 dietary supplements sold in Thailand. This is the first case series report to inform health care providers about nephrotoxicity related to C. militaris supplements.Case presentationEleven patients had acute kidney injury (AKI) related to dietary supplements of C. militaris, which mainly contained cordycepin. Most of these patients from central Thailand (2018–2021) were elderly and five patients had chronic kidney disease stage 3 to 5. Two patients developed AKI requiring dialysis. The causality of AKI related to C. militaris was assessed by the modified Naranjo algorithm and a probable relationship was found between C. militaris and AKI (range from 6–8 scores). Two potential mechanisms of nephrotoxicity from C. militaris were cyclooxygenase-2 inhibition and direct toxicity at kidney tubule.ConclusionsPatients with kidney insufficiency and elderly should avoid using health products containing C. militaris until further clinical research determines such supplementation safe and effective.