Nefopam, a centrally acting analgesic, has been used to control postoperative pain. Reported adverse effects are anticholinergic, cardiovascular or neuropsychiatric. Neurologic adverse reactions to nefopam are confusion, hallucinations, delirium and convulsions. There are several reports about fatal convulsive seizures, presumably related to nefopam. A 71-year-old man was admitted for surgery for a lumbar spinal stenosis. He was administered intravenous analgesics : ketorolac, tramadol, orphenadrine citrate and nefopam HCl. His back pain was so severe that he hardly slept for several days; he even needed morphine and pethidine. At 4 days of administration of intravenous analgesics, the patient suddenly started generalized tonic-clonic seizures for 15 seconds, and subsequently, status epilepticus; these were not responsive to phenytoin and midazolam. After 3 days of barbiturate coma therapy the seizures were controlled. Convulsive seizures related to nefopam appear as focal, generalized, myoclonic types, or status epilepticus, and are not dose-related manifestations. In our case, the possibility of convulsions caused by other drugs or the misuse of drugs was considered. However, we first identified the introduced drugs and excluded the possibility of an accidental misuse of other drugs. Physicians should be aware of the possible occurrence of unpredictable and serious convulsions when using nefopam.
Keywords: Adverse drug reaction; Barbiturate; Nefopam; Status epilepticus.