A Case of Mirtazapine Induced Restless Legs Syndrome

Bahk, Won Myong; Pae, Chi Un; Chae, Jeong Ho; Jun, Taeyoun; Kim, Kwang Soo; Lew, Tae Yul

Abstract

A 56 year-old female patient with major depressive disorder, single episode with unremarkable findings on past medical and psychiatric history visited due to various depressive symptoms. Mirtazapine of 15 mg/day at evening was administered for the control of her depressive symptoms along with alprazolam of 0.5 mg/day at morning and evening for the control of anxiety. On fifth hospitalized day, she complained of creeping and crawling sensation on both legs which was aggravated at night after about one hour of mirtazapine intake and improved with movement. She also had a difficulty in falling a sleep as well as onset of discomfort on both legs. We rendered her discomfort as restless legs syndrome (RLS) due to mirtazapine disposition. Therefore, we maintained mirtazapine of 15 mg/day at evening and added clonazepam of 1 mg/day at morning and evening for the control of RLS. After 7 days observation, the patient complained of aggravated natures of RLS and wanted to stop the drug. Though the effectiveness of mirtazapine for control of depressive symptoms, the drug was switched to paroxetine of 20 mg/day at 16th hospitalized day and 4 days later the RLS was completely terminated.