A six year old child is admitted to the Paediatric ICU for seizures. He has been on tretment with Tacrolimus and Prednisolone. On investigations his blood urea is 68 mg/d1, Serum Sodium is 136 meq/1 likely cause of his seizures-

Ans. is 'd' i.e., Tacrolimus Toxity 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 hypocalcemia, seizures develop when calcium level is below 6 mg/dl. Uremic seizures occur late after delirium, hallucinations and agitation.