A 73-year-old Caucasian woman with a recent diagnosis of
Parkinson disease and a history of
chronic obstructive pulmonary disease,
hyperlipidemia, chronic
osteoarthritis, and
hypothyroidism was hospitalized for altered mental status, weakness, and ambulatory dysfunction. The diagnosis of
Parkinson disease was made approximately four months prior. Despite initiation of
carbidopa-levodopa, the patient's symptoms did not improve, and her mental and physical status declined. The patient was taking
olanzapine 30 mg daily for
bipolar disorder and had a 40-pack-year history of smoking, but she quit smoking approximately four months before this hospitalization. The results of a neurologic evaluation suggested that the patient did not have
Parkinson disease but was possibly experiencing
olanzapine toxicity secondary to smoking cessation.
Carbidopa-levodopa was discontinued. Psychiatry was consulted, and a monthlong cross-taper to discontinue
olanzapine and initiate
aripiprazole with a target dosage of 20 mg daily was recommended. During the course of
therapy, the patient's level of alertness and
bradykinesia improved. Overall, it was noted that her extrapyramidal symptoms were gradually improving; two days before hospital discharge, she was noted to have no definite remaining evidence of
parkinsonism. In this case, use of the Naranjo et al.
adverse-drug-reaction probability scale and the drug interaction probability scale indicated that the adverse effects were probably related to the interaction between smoking and
olanzapine.
CONCLUSION: