Renally Dosed Cefepime Leading to Cefepime-Induced Neurotoxicity: A Case Report

Cefepime is a broad-spectrum fourth-generation cephalosporin with activity against both gram-positive and gram-negative bacteria, including Pseudomonas aeruginosa. Cefepime is most commonly used for urinary tract infections, soft tissue infections, and febrile neutropenia. Up to 15% of ICU patients on cefepime may experience cefepime-induced neurotoxicity (CIN), with risk factors including renal dysfunction, excessive dosage, elevated serum cefepime concentrations, and history of prior brain injury. The adverse effects of CIN, including encephalopathy, seizures, and coma can be resolved with drug cessation, antiepileptics, or hemodialysis. Here, we present the case of CIN in a 59-year-old female patient with long-term cefepime antibiotic prescription for Pseudomonas bacteremia and endocarditis with multiple risk factors for reduced renal function. We discuss the relevant risk factors and preventive measures that may have prevented her from developing CIN, as well as the importance of early recognition and prevention of CIN in patient care.

Assessing seizure liability in vitro with voltage-sensitive dye imaging in mouse hippocampal slices

Non-clinical toxicology is a major cause of drug candidate attrition during development. In particular, drug-induced seizures are the most common finding in central nervous system (CNS) toxicity. Current safety pharmacology tests for assessing CNS functions are often inadequate in detecting seizure-inducing compounds early in drug development, leading to significant delays. This paper presents an in vitro seizure liability assay using voltage-sensitive dye (VSD) imaging techniques in hippocampal brain slices, offering a powerful alternative to traditional electrophysiological methods. Hippocampal slices were isolated from mice, and VSD optical responses evoked by stimulating the Schaffer collateral pathway were recorded and analyzed in the stratum radiatum (SR) and stratum pyramidale (SP). VSDs allow for the comprehensive visualization of neuronal action potentials and postsynaptic potentials on a millisecond timescale. By employing this approach, we investigated the in vitro drug-induced seizure liability of representative pro-convulsant compounds. Picrotoxin (PiTX; 1-100 μM), gabazine (GZ; 0.1-10 μM), and 4-aminopyridine (4AP; 10-100 μM) exhibited seizure-like responses in the hippocampus, but pilocarpine hydrochloride (Pilo; 10-100 μM) did not. Our findings demonstrate the potential of VSD-based assays in identifying seizurogenic compounds during early drug discovery, thereby reducing delays in drug development and providing insights into the mechanisms underlying seizure induction and the associated risks of pro-convulsant compounds.

New Onset Non-Convulsive Status Epilepticus Despite Cefepime Renal Dose Adjustment

Cefepime, a widely used fourth-generation cephalosporin for coverage of both gram-positive and gram-negative bacteria, has been reported to have associated neurological adverse effects. These effects have been seen mostly in patients mostly with impaired renal function, and currently, dosing is based on creatinine clearance to reduce its toxic effect profile. Despite renal dose adjustment, we present a case of a 40-year-old woman who was managed for Escherichia coli bacteremia, acute kidney injury, and hemorrhagic shock. About 96 hours after cefepime therapy was commenced, she was noted to be twitching with passive movement of her upper limb and myoclonus of the facial muscles. Her workup including computed tomography (CT) scan of the head and magnetic resonance imaging (MRI) brain were negative. Electroencephalograph (EEG) showed 2 Hertz sharply contoured triphasic form rhythmic waves suggestive of nonconvulsive status epilepticus (NCSE). She received antiseizure medications and later had hemodialysis for effective clearance of cefepime. She had significant improvement in her neurological status following hemodialysis and a repeat EEG showed no further seizure activity. Clinicians should be aware of the risk of NCSE in patients on cefepime despite renal dose adjustment. Once identified, immediate discontinuation of the offending drug, treatment with benzodiazepines, and clearance of the medication with hemodialysis is recommended. 

Antibiotic-induced epileptic seizures: mechanisms of action and clinical considerations

In recent years, there has been growing interest in the development of epileptic seizures as an adverse effect of antibiotic therapy. The most commonly accepted mechanisms underlying the development of antibiotic-induced seizures include direct- and indirect gamma-aminobutyric acid (GABA) antagonism, inhibition of GABA synthesis, and glutaminergic N-methyl-D-Aspartate (NMDA) receptor agonistic activity. Inhibitory pathway inhibition leads to increased neuronal excitability and lowered seizure threshold. Blockage of myoneural presynaptic acetylcholine release, mitochondrial dysfunction, interference of neural protein synthesis, and oxidative stress caused by the generation of neurotoxic radicals also contributes to the development of neurotoxicity. Patients with pre-existing risk factors such as renal or hepatic insufficiency, central nervous system pathology, neurological diseases, history of epilepsy or seizures, critical illness, and increased age are more susceptible to seizure development as a consequence of antibiotic therapy. Administration of antibiotics, together with antiseizure drugs, may also lead to enhanced seizure risk due to drug interactions, which predisposes to alterations in drug metabolism and therapeutic efficacy.

[Drug-induced seizures: prevalence, risk factors, treatment and prevention]

There is a growing interest to the problem of drug-induced epileptic seizures (ES) due to their relatively high prevalence, poor prognosis, a large number of different drugs associated with the development of drug-induced ES, and low awareness among general practitioners. Drug-induced ES are most often associated with the use of antidepressants, antipsychotics, antiepileptic drugs (overdose or as a result of discontinuation), antibiotics, immunosuppressants and immunomodulators, antitumor agents, analgesics, central nervous system stimulators, anesthetics etc. The prevalence of drug-induced ES varies with different drugs. It is estimated that about 6.1% of the first occurring ES are drug-induced. Risk factors for drug-induced ES include a history of epilepsy or ES, cancer, blood-brain barrier dysfunction, several concomitant neurological diseases, mental disorders, childhood, old and very old age, fever, impaired liver metabolism in patients with liver diseases, impaired drug excretion in patients with kidney diseases, polypharmacy, pharmacokinetic properties of the drugs themselves, allowing them to penetrate the blood-brain barrier in the central nervous system (lipophilicity, transport and communication with blood plasma proteins), drug concentration in blood serum, method and frequency of drug administration, single and daily doses of drugs. No clinical guidelines for the management of patients with drug-induced ES are available. It is recommended to identify patients at risk: elderly patients, patients with impaired liver and kidney function and patients receiving drugs that can cause ES and/or lower the seizure threshold. Benzodiazepines are the first-line treatment in drug-induced status epilepticus, barbiturates and propofol are the second-line treatment. The general principles for the prevention of drug-induced ES include careful selection of the optimal dose of drugs that can cause ES, especially in patients with impaired liver and/or kidney function, monitoring of several parameters in blood serum (for example, liver enzymes, electrolytes, glucose etc.), monitoring of the blood plasma concentration of certain drugs, avoiding the simultaneous administration of several drugs that stimulate the central nervous system, and a rapid discontinuation of such drugs.