Fluvoxamine induced oculogyric dystonia and manic switch in a patient with obsessive compulsive disorder
A 21-year-old, Muslim male belonging to middle socio-economic status and educated up to intermediate degree had a family history of bipolar affective disorder in his paternal grandfather. He was well adjusted premorbidly and presented with 4 years of illness with no obvious precipitating factor, characterized by repeated, intrusive doubts about symmetry and repeatedly arranging household articles like clothes, shoes, furniture, books etc. He also had doubts on the linearity of the sentences he writes on pages and would write several times before he moved to the next page. He clearly was distressed with these symptoms and for the past 4 months was also complaining of predominant low mood, decreased interest in activities, ideas of decreased self-worth and pessimistic future. He was admitted as an inpatient with a diagnosis of OCD and comorbid moderated depressive episode according to ICD-10. His routine blood investigations including thyroid profile, computed tomography scan brain and electroencephalography were normal. He scored a total of 24 on Yale-Brown Obsessive Compulsive Scale (Y-BOCS) and 15 on Hamilton Depression (HAM-D-17) Rating Scale. He was started on morning dose of fluvoxamine, with an initial dose of 50 mg to be hiked by 50 mg every 4th day. By the 2nd week, he started reporting of improvement especially in depressive symptoms (HAM-D-17 scores reduced to 10 whereas on Y-BOCS, he scored 22). On the 11th day of admission, he complained of oculogyric dystonia characterized by involuntary sustained upward gaze in both his eyes during morning hours. There were no signs and symptoms suggestive of pseudo-parkinsonism or any other movement disorders. He was administered injection promethazine 50 mg stat intramuscularly and the symptom subsided within an hour. Dose of fluvoxamine was decreased to 150 mg and further hiking was planned every 8th day. This symptom did not recur subsequently. By 25th day the fluvoxamine dose was increased to 250 mg and he showed significant improvement in both obsessive (Y-BOCS total score –14) and depressive symptoms (HAM-D-17 total score – 4). However, 2 days later, mental status examination revealed over familiar manner of relating, over productive speech, euphoric affect and inflated self-esteem. He scored 16 on Young Mania Rating Scale (YMRS). Fluvoxamine dose was reduced to 150 mg and 900 mg lithium was added, which was later increased to 1050 mg to obtain optimal serum level, i.e., 0.72 meq/L. He showed an improvement in manic symptoms within 10 days (YMRS total score –3) and maintained the improvement shown in obsessive symptoms.\nThere is a clear temporal relationship between the occurrence of dystonia and relatively faster titration in the dose of fluvoxamine to 200 mg. And reduction in the dose and subsequent slow titration was helpful. Also, temporal relationship between the occurrence of manic switch and dose of fluvoxamine was established. This particular class of drugs is known to cause the spectrum of side-effects as in our case. However, specific case of fluvoxamine causing oculogyric dystonia has not been reported in the literature. While considering the manic switch, a positive family history of bipolar illness in this case might have predisposed the patient to a manic switch; but neurobiological mechanisms of fluvoxamine might be sufficient to trigger a manic switch. The Naranjo adverse drug reaction probability score for oculogyric dystonia was –6 and for the induced manic switch was –5; both suggesting a “probable” association with administration of fluvoxamine.