Tactile Hallucinations with Fluoxetine and Methylphenidate

Abstract

[Author Affiliation]Gurvinder Singh Arora. 1 Department of Child and Adolescent Psychiatry, University of Illinois at Chicago, Chicago, Illinois.Harpreet Kaur Arora. 2 Christian Medical College, Vellore, India.Jaskirat Sidhu. 3 New York, New York.Fedra Najjar. 1 Department of Child and Adolescent Psychiatry, University of Illinois at Chicago, Chicago, Illinois.Address correspondence to: Gurvinder Singh Arora, MD, Department of Child and Adolescent Psychiatry, University of Illinois at Chicago, 1747 West Roosevelt Road, Chicago, IL 60608, E-mail: vinciarora@gmail.comTo The Editor:Fluoxetine, a serotonin reuptake inhibitor (SSRI) is a commonly used antidepressant in children. Among all SSRIs, it has the longest half-life (fluoxetine, 4-6 days; norfluoxetine, its metabolite, 9.3 days). Methylphenidate is one of the most commonly used stimulants in children and has a short half-life (2-3 hours). Methylphenidate has been known to cause tactile, visual, and auditory hallucinations at therapeutic doses (Ross 2006). Tactile hallucinations are a rare phenomenon with fluoxetine. There have been reports of hallucinations with the use of fluoxetine in combination with other medications (Achamallah 1992; Bourgeois et al. 1998; Coleman et al. 2003) and when used in other ailments comorbid with depression (Lauterbach 1993; Omar et al. 1995). There is an isolated case report of tactile hallucinations that started when the patient was on a combination of methylphenidate and fluoxetine (Coskun et al. 2008). We present a second case further contributing to the evidence of this serious side effect of tactile hallucinations in a patient on a combination of methylphenidate and fluoxetine, limiting compliance to treatment.Case ReportX was an 8-year-old African American male weighing 28.6 kg, with no past psychiatric history, who was initially brought in by his mother for the treatment of his oppositional behavior and crying spells. On further evaluation, it was determined that he had been hyperactive, impulsive, and inattentive and met criteria for attention-deficit/hyperactivity disorder (ADHD). In addition, he also reported multiple depressive symptoms, including depressed mood, loss of interest, decreased energy level, and poor concentration. He was started on methylphenidate 5 mg twice daily, given the fact that his brother, who had had similar symptoms, responded very well to methylphenidate. Methylphenidate dose was increased to 10 mg twice daily 1 week later. Because the patient's mother reported increased physical aggression on this higher dose, it was titrated down to 5 mg twice daily. The patient was started on fluoxetine 4 mg daily for depression, after having been on methylphenidate for 2 weeks. This regimen was continued for 3 more weeks, after which the methylphenidate dose was increased to 10 mg twice daily, after ascertaining that the increased physical aggression was not caused by methylphenidate. While on this dose of methylphenidate for another week, the patient reported a sensation that he described as crawling over his skin, while he was watching television. He denied any visual or auditory hallucinations. This sensation lasted a few minutes and resolved on its own. Two days later, the patient woke up early because of a similar sensation over his skin and face, looking for ants over his body. He walked with caution, thinking that there might be ants on the floor. The sensation lasted for ∼1 hour and then went away. Subsequently, the patient had this sensation off and on, approximately once a day, and it scared him. These tactile hallucinations were thought to be secondary to methylphenidate. Methylphenidate was discontinued after ∼7 weeks of treatment. The tactile hallucinations persisted even 1 week after methylphenidate was discontinued. Fluoxetine was discontinued as well, a week after stopping methylphenidate. …