Many drug names can look or sound like other drug names, which leads to confusion and potentially harmful medication errors. While various types of drug names exist, brand (proprietary) names are most commonly confused. Examples of the numerous drug names that have been confused because they look and/or sound similar include Celebrex (celecoxib), Cerebyx (fosphenytoin), and Celexa (citalopram). Factors such as poor handwriting and clinical similarity may exacerbate the problem. This problem can be alleviated through actions by regulatory agencies, pharmaceutical manufacturers, healthcare professionals, and patients. To address the problem, significant changes in the pharmaceutical regulatory process have occurred in the US and Europe.