Brimonidine Eye Drops Causing Encephalopathy in a Patient With Advanced Chronic Kidney Disease

Brimonidine eye drops are frequently prescribed for the treatment of glaucoma and ocular hypertension in adults. Systemic toxicities including neurological side effects have been reported with its use, especially in the paediatric population. In this report, we present a case of encephalopathy secondary to the use of brimonidine eye drops in a patient with underlying advanced chronic kidney disease, who recovered promptly after drug cessation. Herein, we also review the pharmacokinetics of eye drops leading to their systemic side effects, especially in the context of renal impairment. We also explore the possibility of extracorporeal treatment, such as by haemodialysis, for the treatment of these manifestations. This case demonstrates the need to clarify a patient's drug history and stop offending medications early on in a patient with delirium, while treatments such as antidotes or extracorporeal treatment are being considered.