828 - Visual hallucination in a patient using duloxetine for treatment of pain

Case Diagnosis: Duloxetine is a serotonin-noradrenaline reuptake inhibitor used to treat major depressive disorder (MDD) and chronic pain. Previous studies demonstrated the safety profile of duloxetine compared to other commonly used medications for these conditions including gabapentin and pregabalin. We present a case report of a patient who developed visual hallucinations after starting duloxetine.

Case Description: Patient is a male in his 30s with history of post-traumatic stress disorder and MDD not on psychotropic medications, with chronic pain due to subacromial impingement, lumbar stenosis with radiculopathy, and cervical spondylosis with radiculopathy. For pain, the patient was on baclofen 10mg three times a day, acetaminophen 1000mg as needed, and meloxicam 15mg daily, all without reported side effects. The patient was previously on gabapentin and pregabalin without reported adverse effects. He was started on duloxetine 20mg daily for 7 days, then 40mg daily for 7 days, then 60mg daily. He reported development of visual hallucinations of seeing a human face that is melting/burning approximately 1mo after being on duloxetine 60mg daily. He denies history of visual hallucinations prior to starting duloxetine. The pt was discontinued on duloxetine and started on mirtazapine and visual hallucinations resolved.

Discussions: Duloxetine increases the level of serotonin as well as dopamine especially in the prefrontal cortex via reuptake inhibition, which may lead to the occurrence of hallucinations. A previously published case report demonstrated visual hallucinations in a patient with MDD started on duloxetine however was also on other medications including mirtazapine, pregabalin, and amitriptyline, which could also contribute to the occurrence of hallucinations.

Conclusions: To our knowledge, this is the first case report of a patient who developed visual hallucinations in the absence of being on other psychotropic medications associated with hallucinations. Although duloxetine has been shown to be relatively safe, it may be associated with development of visual hallucinations.