L MCBRIDE1, J WANG1, P HO1,2,3, D LANGSFORD1,2
1Northern Health, 2University of Melbourne, 3Monash University,
Background: Dabigatran can be reversed with a single dose of idarucizumab in patients with normal renal function. We present a case of acute kidney injury with dabigatran toxicity requiring three doses of idarucizumab and daily haemodialysis.
Case Report: A 71-year-old man presented with acute gastrointestinal bleeding (haemoglobin 78g/L) and non-oliguric acute kidney injury (creatinine 1414umol/L) 6 weeks after a stroke and commencement of dabigatran (when he had normal renal function). Renal tract imaging, vasculitis and autoimmune screens were normal. His INR was 8.7 (initial APTT not available). Dabigatran was ceased and idarucizumab administered. Post-dose rebound coagulopathy occurred (APTT 89.7) indicating a further idarucizumab dose. Immediately following this dose a temporary dialysis line was inserted and the patient was commenced on increasingly efficient daily haemodialysis, at which time the dabigatran level was undetectably high. At 72 hours the patient was haemodynamically unstable with haemoglobin 64g/L and had rebound in coagulopathy (APTT 45), indicating a third dose of idarucizumab. We observed significant rebound in dabigatran and APTT both following the administration of idarucizumab and haemodialysis. The dabigatran level gradually declined to non detectable over 14 days of daily haemodialysis, when a renal biopsy revealed severe acute interstitial nephritis. Detailed medication history failed to identify a known causative agent. The patient was commenced on 60mg prednisolone daily and haemodialysis was withdrawn 6 weeks later following renal recovery.
Conclusions: This is the first report of biopsy proven dabigatran associated acute interstitial nephritis and also the first report of dabigatran toxicity requiring three doses of idarucizumab. Importantly, the three doses were not sufficient to reverse dabigatran and efficient daily hemodialysis was required to achieve complete dabigatran clearance.
Nephrologist and General Physician at Northern Health