Prolonged Delirium with Psychotic Features from Omega Conotoxin Toxicity

Abstract

To the Editor: Patients with neuropathic pain constitute a considerable proportion of the population of patients with chronic pain for which there are less than optimal treatment options. The scientific literature provides information on omega conotoxin efficacy and safety in the management of chronic pain conditions ⇓. A synthetic version, ziconotide, is a first line intrathecal (IT) alternative agent to opioids in the management of cancer pain ⇓. We describe a case of prolonged delirium with psychotic features in a patient with peripheral neuropathy on a gradual escalating dose of ziconotide. A 37-year-old man with a history of idiopathic small fiber peripheral neuropathy unresponsive to usual treatment with opiate analgesics was started on IT ziconotide for better pain control 1 year before he presented to our center with a 3-day history of confusion, hallucination, and tremor. These symptoms started a day after his home was sprayed with insecticide. He had associated symptoms of loss of appetite, …