Abstracts

RATIONALE: Many medications are listed in the PDR as having a potential for inducing seizures. For many the effect is negligible and the warning is ignored. In the PDR, ciprofloxacin has a warning and imipenem a precaution that there is a potential for seizures. The mechanism of pro-convulsant action is probably GABA antagonism. Many physicians appear to be unaware of the significant potential for these drugs to produce seizures.
METHODS: We have reviewed our outpatient charts of epilepsy patients who had seizures correlating with use of ciprofloxacin. We have also reviewed reports to the pharmacy of seizures associated with use of ciprofloxacin and imipenem.
RESULTS: Three clinic patients were identified who called the office for seizures and who had been started on ciprofloxacin in the prior one to two days. These patients had infrequent seizures (0-2/year or only simple partial seizures. All had minor infections without significant fever.
From the inpatient service, six cases were reported to the pharmacy of seizures related to ciprofloxacin and/or imipenem. Four of these charts have been located and reviewed. All were intensive care unit (ICU) patients. One patient was admitted with an exaccerbation of chronic inflammatory demyelinating polyradiculopathy and developed status epilepticus during treatment with ciprofloxacin that was refractory to phenytoin and required propofol. Her seizures resolved with discontinuance of ciprofloxacin. A second patient in the ICU with sepsis secondary to abdominal surgery developed complex partial seizures which began with ciprofloxacin being changed to imipenem. Mental status improved with meropenem. A third patient developed complex partial status epilepticus about 24 hours after liver transplant that was readily controlled with phenytoin. One week later, refractory status epilepticus occurred while she was being treated with both ciprofloxacin and imipenem. A fourth patient with Alzheimer[ssquote]s disease became septic. She developed multifocal myoclonus while being treated with ciprofloxacin. In this case, severe metabolic derangement including renal failure were alternative causes.
CONCLUSIONS: We recommend avoiding ciprofloxacin and imipenem in patients with a history of epilepsy. However, ciprofloxacin and imipenem may lower seizure threshold and cause seizures in patients without a prior history of epilepsy. The cases identified in the ICU were reported as drug adverse events by the primary physician. We suspect many more cases occurred but went unreported. We are currently searching the hospital data base for all patients treated with ciprofloxacin and/or imipenem and also having an EEG to better estimate the occurrence of neurologic sequelae to these drugs.