The recommended dose of ertapenem poses a potential risk for central nervous system toxicity in haemodialysis patients - case reports and literature reviews.

Abstract

Dosage adjustment of 500 mg ertapenem daily is recommended for patients with advanced kidney disease. 30% of ertapenem is cleared by a session of haemodialysis (HD). However, because most published carbapenems studies have excluded patients on dialysis, little is known about the dosing of ertapenem to avoid central nervous system (CNS) toxicity in regular HD patients. We report of four patients who developed CNS toxicity in such patients. The 4 HD patients developed unexplained CNS toxicity manifested as seizures, hallucination and cognitive dysfunction after receiving 3-7 consecutive recommended doses of ertapenem. Their symptoms of CNS toxicity were completely resolved within 8 days after discontinuation of ertapenem. In one of our presented cases, we demonstrated the very high level of plasma ertapenem accumulating with several consecutive doses. Cognitive function gradually recovered in line with a corresponding decline in blood level of ertapenem. This is the first report of ertapenem-associated CNS toxicity in patients on regular HD and utilizing the plasma ertapenem concentration to demonstrate the causal relationship. The recommended dosage of 500 mg ertapenem daily may be still too high in regular HD patients, especially in Asians, owing to their relatively small body size. An increased awareness of ertapenem-associated CNS toxicity would avoid unnecessary examinations, hospitalization, and potentially catastrophic complications.