Ertapenem renal insufficiency

Carbapenems penetrate body tissues and fluids well, including the cerebrospinal fluid. All are cleared renally, and the dose must be reduced in patients with renal insufficiency. The usual dose of imipenem is 0.25-0.5 g given intravenously every 6-8 hours (half-life 1 hour). The usual adult dose of meropenem is 1 g intravenously every 8 hours. Ertapenem has the longest half-life (4 hours) and is administered as a once-daily dose of 1 g intravenously or intramuscularly. Intramuscular ertapenem is irritating, and for that reason the drug is formulated with 1% lidocaine for administration by this route. 

F Meropenem is the best choice. Ertapenem and ampicillin/sul-bactam do not adequately cover Acinetobacter baumannii. Also, with her history of renal insufficiency and seizures, imipenem would not be appropriate because the patient would be at increased risk for seizures. 

Eriapenem Ertapenem came on to the market around 10years ago. Of 30patients taking ertapenem three had seizures [2T]. All had moderate renal insufficiency (creatinine clearances 44, 54, and 56 ml/minute) and all had received intravenous ertapenem 1 g/day. All three had some kind of nervous system disorder, but only one had previously had seizures. Two were given prophylactic antiepileptic drugs. 

Fica AE, Abusada NJ. Seizures associated with ertapenem use in patients with CNS disorders and renal insufficiency. Scand J Infect Dis 2008 40 983-5. 

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