Parkinsonism and Elevated Lactic Acid with Sertraline

Abstract

Dear Editor: A few reports of sertraline-induced akathisia and dystonia are available, but reporting on sertraline-induced Parkinsonism is negligible (1). We report a case of Parkinsonism associated with sertraline use. To our knowledge, this is the first case in the literature to highlight a possible relation between selective serotonin reuptake inhibitors (SSRIs) and lactic acid metabolism. Case Report Mrs L, aged 45 years, is a married, middleclass housewife. She was premorbidly well adjusted and had no significant psychiatric or medical history and no significant family history. She presented with a 2-month history of persistent sadness, frequent crying spells, suicidal ideation, agitation, feelings of hopelessness and worthlessness, disturbed biological functioning, and weight loss of 5 kg. Her illness was precipitated by severe financial losses in her husband's business. Moreover, he had taken a large loan to start his business, and his creditors were demanding payment. Their visits to the home caused her to become markedly restless and apparently unresponsive to her surroundings for periods of 30 minutes to 2 hours. She emerged from these spells when cold water was sprinkled on her face. Mrs L was hospitalized in a private nursing home and given tablet alprazolam 0.5 mg daily and intravenous fluid with parental B complex. She was later referred to our hospital, where all medication was discontinued on admission. She was diagnosed with major depression with conversion disorder and was started on sertraline 50 mg daily and clonazepam 1 mg daily. We increased her sertraline to 100 mg daily on the fourth day of admission. The next day, she developed excessive salivation, mask-like facies, bradykinesia, cogwheel rigidity, tremors of both hands, and monotonous speech. We immediately discontinued sertraline, and she was given intramuscular promethazine 50 mg, with partial response. We sought the opinion of a neurologist on the same day, and Mrs L was given a diagnosis of possible sertaline-induced Parkinsonism. According to the Extrapyramidal Symptom Rating Scale (2), her Parkinsonism was moderately severe. We started her on trihexyphenidyl 2 mg daily, increased to 6 mg daily over a period of 7 days. She was maintained on this dosage for 10 days, and her extrapyramidal symptoms (EPS) fully remitted. However, when trihexyphenidyl was tapered to 2 mg daily, the Parkinsonism symptoms reappeared. We therefore increased the dosage of trihexyphenidyl back to 6 mg daily, with successful results. Because her symptoms reappeared, she was investigated thoroughly. Magnetic resonance imaging (MRI) of the head revealed bilateral basal ganglia focal hyperintensities without any specific lesion. She had a normal biochemical profile for blood sugar, urea, serum creatinine, calcium phosphorus, and alkaline phosphatase. …