A six-year-old child is admitted to the Paediatric ICU for seizures. He has been on treatment with Tacrolimus and Prednisolone. On investigations his blood urea is 68 mg/dl, Serum Sodium is 136 meq/l likely cause of his seizures –

Tacrolimus neurotoxicity is an established cause for 'seizures' and the most likely reason for seizures in this child. In hyponatremia, seizures usually develop when sodium levels decrease below 125 meq/L. In hypocalcaemia, seizures develop when calcium level is below 6 mg/dl. Uremic seizures occur late after delirium, hallucinations and agitation.