Normeperidine-induced seizures in hereditary coproporphyria. Seizures are common in acute exacerbations of hepatic porphyria, even though the etiology is not identified in most cases. We have reported a case of normeperidine-induced seizures in a patient with hereditary coproporphyria. Although meperidine is commonly used for pain control during acute attacks in these patients, this report suggests that meperidine is not a good analgesic choice in porphyria. Normeperidine-induced seizures in patients with porphyria may be treated by withdrawal of meperidine therapy and selective use of anticonvulsants. 