Quetiapine is known to have virtually no risk of extrapyramidal symptoms (EPS) and tardive dyskinesia (TD) [1]. I am aware of one published case report of EPS associated with quetiapine [2]. I now present three further cases of EPS associated with quetiapine.Mr A, a 31-year-old with chronic paranoid schizophrenia, had been stable on 20 mg/day of olanzapine and 300 mg/day of bupropion sustained release. As a response to weight gain, olanzapine was tapered off, and 50 mg twice a day of quetiapine was started and raised to 300 mg/day; 300 mg/day of bupropion sustained release was maintained as before. Two weeks after taking 300 mg/ day quetiapine, Mr A complained that his arms and legs were stiff, his jaw became tight, and his tongue felt thick. He showed cogwheel rigidity of both elbows. Benzatropine 2 mg intramuscular relieved these symptoms.Ms B, a 46-year-old with chronic paranoid schizophrenia, had been stable on 10 mg/day of olanzapine. Recently, she manifested cogwheel rigidity and resting tremor of both hands. Olanzapine was discontinued, and the rigidity and tremor abated. Quetiapine 50 mg twice a day was initiated and raised to 200 mg daily. After 2 weeks, she showed mild cogwheel rigidity of both elbows and wrists and resting tremor of both hands. Benztropine 1 mg twice daily resulted in a reduction of these symptoms.Mr C, a 37-year-old with schizoaffective disorder, had been stable for 2 years on 100 mg/day of quetiapine, 50 mg/day of thioridazine, 2 mg/day of trihexyphenidyl and 500 mg/day of diavalproex. Thioridazine and trihexyhenidyl were discontinued, quetiapine was raised to 200 mg daily; diavalproex was maintained as before. After 3 weeks, Mr C showed typical parkinsonian tremor of both hands and cogwheel rigidity of both elbows and wrists. As trihexyphenidyl produced dry mouth, 200 mg of amantadine twice daily was initiated with reduction of the tremor and rigidity.Attention should be paid to the potential occurrence of EPS in patients on quetiapine. Of course, association in these cases does not necessarily mean cause.
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