Nayomi Shermila Jarasinghe

Queensland Health, Australia 

BIOGRAPHY

Dr.N.S.Jayasinghe is a senior registrar in internal medicine in Central Queensland Health Services. She possess 8 years of post graduate experience with MBBS and MD(internal medicine )degrees. She is an associate lecturer in University of Queensland.She was an author of many internationally published articles. She is actively involved in ongoing research in her working place. Her research interests are non communicable diseases, infectious diseases and hematolgy.



ABSTRACT

Nivolumab induced severe hypokalemia causing acute flaccid paralysis; A case report 

Nayomi Shermila Jayasinghe¹, Sudhakar Vemula²
1Department of Medicine, Rockhampton hospital, Queensland, Australia
2Department of Oncology, Rockhampton hospital, Queensland, Australia

Background: Nivolumab is an Anti-programmed death-1 agent widely used in melanoma and variety of other cancer treatment. This treatment is related to a unique spectrum of adverse events, called immune-related adverse events (irAEs) (Weber, Postow, Lao & Schandendorf 2016).Non immune related adverse effects are less common. Nivolumab induced hypokalemia is rare (Postow, Volchok 2016).It is mostly associated with classical Hodgkin’s lymphoma treatment (Nivolumab: Drug information, n.d. Lexicomp).Nivolumab induced severe hypokalemia leading to flaccid paralysis has not been reported in published literature. Thus we report the first case.

Case presentation: Eighty two year old lady presented for tenth cycle of Nivolumab for poorly differentiated lung adeno carcinoma. Full blood count, renal functions and electrolytes on the same day prior to therapy were normal. Potassium was 3.9mmol/l. She did not have diarrhoea, vomiting, neurological weakness or adrenal disorders. She was not on any medications causing hypokalaemia.  Thirty minutes into the infusion she developed lower limb numbness and it gradually progressed to upper limb weakness, swallowing difficulty and difficulty in opening eyes. Examination revealed hypotonia, 2/5 muscle tone, afreflexia, bilateral facial muscle weakness and bilateral ptosis. Urgent bloods showed hypokalemia of 2.1mmol/l with normal full blood count, inflammatory markers, renal functions, adrenal functions and lumbar puncture. She received intravenous potassium chloride (KCl) 40mmol followed by oral KCl tablets. Soon after KCl infusion her weakness recovered completely. Magnetic resonance imaging of brain and spine, nerve conduction studies did not reveal any myelopathy or conduction abnormalities. She made a full recovery and continued to get Nivolumab infusions with caution.

Conclusion: Increased awareness and high degree of clinical suspicion is needed among clinicians for timely diagnosis of this rare complication of Nivolumab. We recommend vigilant monitoring of electrolytes when treating with this medication.