Lamotrigine withdrawal may worsen RBD symptoms

Rapid eye movement (REM) behavior disorder (RBD) is a rapid eye movement parasomnia, which in its symptomatic type could be induced by the introduction or the discontinuation of several drugs and substances. No references for antiepileptic drugs and especially for lamotrigine are known regarding pharmacologically induced RBD.

We report a case of a 68-year-old man already suffering from RBD, who developed very brief episodes of epigastric discomfort followed by impaired consciousness and was given a diagnosis of epilepsy. Lamotrigine was started at 25 mg/d, reached a maximum of 100 mg/d after 2 months and was retained at this dose for 1 more month. During this period there was a slight decrease in the episodes of impaired consciousness and no appreciable changes in the frequency and intensity of RBD symptomatology. Immediately following the abrupt discontinuation of lamotrigine, RBD symptomatology was severely aggravated, with dreams becoming more vivid and frightening and occurring almost every night. RBD symptomatology gradually subsided over 2 months, reaching levels comparable to those before lamotrigine. The impaired consciousness episodes remained unaffected and were considered to be nonepileptic.

Our findings suggest that abrupt withdrawal of lamotrigine may worsen symptoms of comorbid idiopathic RBD.