Carbidopa/Levodopa Pharmacy Errors in Parkinson's Disease

Outpatient pharmacy errors are common, but little is known about their occurrence in Parkinson's disease (PD). We prospectively studied carbidopa/levodopa pharmacy errors in a cohort of PD outpatients. Over 1 year, pharmacy errors occurred in 8/73 (11%) subjects treated with this medication, producing adverse drug events (ADEs) in 7/8 (87.5%) and increased healthcare utilization in 6/8 (75%) cases. The most common errors were substitution of controlled-release for immediate-release carbidopa/levodopa 25/100 mg (5/8; 62.5%) or dispensation of the wrong carbidopa/levodopa dosage (2/8; 25%). All errors involved ongoing prescriptions, including three interpharmacy transfers. Three subjects (37.5%) questioned pharmacy staff about the change in appearance of the tablets, but the error was corrected in only 1/3 of these cases. Carbidopa/levodopa outpatient pharmacy errors are a common, preventable cause of morbidity and excessive healthcare utilization in PD. Education of healthcare providers, patients, and pharmacy staff is warranted to reduce these errors and associated ADEs. (C) 2010 Movement Disorder Society.