Multiple drugs abuse/misuse/interactionVarious toxicities: case report A 38-year-old woman developed withdrawal symptoms after fentanyl and clonazepam withdrawal. Additionally, she developed altered mental status due to concomitant administration of phenibut and diphenhydramine, and paranoia and impulsivity following phenibut misuse and intoxication. Additionally, she had fentanyl, clonazepam and gabapentin abuse.The woman presented to an emergency department for trauma evaluation in March 2020 after falls from the 3 rd floor. Two days prior to the hospitalisation, she was self-treated with phenibut for anxiety, and fentanyl and clonazepam withdrawal management [dosage not stated]. She came to know about phenibut from her friend and purchased it via an online vendor. She reported injecting fentanyl 2 g/day, oral nonprescribed clonazepam 5-10 mg/day and nonprescribed oral gabapentin up to 2400mg twice daily. She had severe opioid, gabapentin and benzodiazepine use disorders and 8 months prior, she was treated with buprenorphine, which later stopped as she developed nausea and weight loss [aetiology not stated]. She had history of bipolar spectrum and posttraumatic stress disorders. Earlier, she was prescribed escitalopram, quetiapine and diphenhydramine. Five years prior to the admission, because of her suicidal and homicidal ideation, she was forcefully held in the ED for 3 days after a physical assault. Approximately 2 days prior to her current hospitalisation, she had ingested several teaspoons of phenibut (misuse). After her initial phenibut ingestion, she slept for about 24h. Her partner, who was supporting her self-directed detoxification, reported that upon awakening she showed impulsivity, paranoia and response to internal stimuli by engaging in self-dialogue. Thereafter, on the same day, she was brought to an ED after she left her house without clothes. On the same day, she was sent home; however, she was still not herself, reported by her partner. After back to the home, she ingested diphenhydramine and additional phenibut (quantity unknown). She slept briefly and was became aggressive and impulsive again. Subsequently, she jumped out of third story window, despite her partner's efforts to pull her back in. She was not able to remember the reason for jumping but did not intend to harm herself. On her presentation, she reported that difficulty ambulating with severe electric pain radiating down her spine. Her physical examination demonstrated thoracolumbar tenderness, mydriasis and decreased hip and knee flexor strength. Imaging showed severe spinal stenosis with unstable T12 and L1 fractures; therefore, she underwent emergent neurosurgery. Further, her urine toxicology was positive for fentanyl and benzodiazepines. On the standard hospital immunoassay, phenibut was not detected. Her urine sample was not sent for liquid chromatography/mass spectrometry analysis. She was treated based on her report of phenibut ingestion.The woman's hospital course was complicated by altered mental status which was consider...
