Fan Kuang-Yuan, Liu Hsing-Cheng
*Department of Psychiatry, Taipei City Psychiatric Center, Taipei City Hospital; and †Department of Psychiatry, School of Medicine, Taipei Medical University, Taipei, Taiwan.
Clin Neuropharmacol. 2017 May/Jun;40(3):152-153. doi: 10.1097/WNF.0000000000000214.
Withdrawal symptoms on selective serotonin reuptake inhibitor (SSRI) discontinuation have raised clinical attention increasingly. However, delirium is rarely reported in the SSRI discontinuation syndrome.
We report a case of delirium developing after fluoxetine discontinuation in a 65-year-old female patient with major depressive disorder. She experienced psychotic depression with limited response to treatment of fluoxetine 40 mg/d and quetiapine 100 mg/d for 3 months. After admission, we tapered fluoxetine gradually in 5 days because of its limited effect. However, delirious pictures developed 2 days after we stopped fluoxetine. Three days later, we added back fluoxetine 10 mg/d. Her delirious features gradually improved, and the clinical presentation turned into previous psychotic depression state. We gradually increased the medication to fluoxetine 60 mg/d and olanzapine 20 mg/d in the following 3 weeks. Her psychotic symptoms decreased, and there has been no delirious picture noted thereafter.
Delirium associated with fluoxetine discontinuation is a much rarer complication in SSRI discontinuation syndrome. The symptoms of SSRI discontinuation syndrome may be attributable to a rapid decrease in serotonin availability. In general, the shorter the half-life of any medication, the greater the likelihood patients will experience discontinuation symptoms. Genetic vulnerability might be a potential factor to explain that SSRI discontinuation syndrome also occurred rapidly in people taking long-half-life fluoxetine. The genetic polymorphisms of both pharmacokinetic and pharmacodynamic pathways might be potentially associated with SSRI discontinuation syndrome.
选择性5-羟色胺再摄取抑制剂（SSRI）停药时出现的戒断症状日益引起临床关注。然而，在SSRI停药综合征中，谵妄鲜有报道。
我们报告1例65岁重度抑郁症女性患者在停用氟西汀后发生谵妄的病例。她患有精神病性抑郁症，服用40mg/d氟西汀和100mg/d喹硫平治疗3个月，疗效有限。入院后，因疗效不佳，我们在5天内逐渐减少氟西汀用量。然而，停用氟西汀2天后出现谵妄症状。3天后，我们重新加用10mg/d氟西汀。她的谵妄症状逐渐改善，临床表现恢复至先前的精神病性抑郁状态。在接下来的3周内，我们逐渐将药物剂量增加至60mg/d氟西汀和20mg/d奥氮平。她的精神病性症状减轻，此后未再出现谵妄症状。
与氟西汀停药相关的谵妄是SSRI停药综合征中极为罕见的并发症。SSRI停药综合征的症状可能归因于5-羟色胺可利用性的快速下降。一般而言，任何药物的半衰期越短，患者出现停药症状的可能性越大。遗传易感性可能是解释服用半衰期长的氟西汀的患者也会迅速出现SSRI停药综合征的一个潜在因素。药代动力学和药效学途径的基因多态性可能与SSRI停药综合征潜在相关。
