WEDNESDAY, May 7 (HealthDay News) -- Senior citizens with disabilities are twice as likely as their non-disabled counterparts to being taking at least one prescription drug deemed inappropriate for people 65 or older, according to new research.

The study, based on 2004 data, reports that about a quarter of disabled seniors in the United States have taken one of 33 medications regarded as ineffective or posing a high risk of side effects to the elderly. These drugs include Xanax, Demerol, Darvon and Procardia.

Only 13 percent of seniors without disabilities used these medications, according to the analysis, published in the latest News and Numbers from the U.S. Agency for Healthcare Research and Quality.

The analysis also found the prescription drug misuse ran slightly higher among people with complex disabilities when compared with those having basic disabilities (27 percent vs. 23 percent). A person is considered to have a complex disability if his or her ability to work or socialize is hindered; a person with only limited ability to walk, bathe or perform everyday activities is said to have a basic disability.

Education, but neither race nor ethnicity, appeared to affect the likelihood that seniors would take an inappropriate medication. Disabled seniors with disabilities who did not finish or receive education beyond high school were more likely to use potentially inappropriate drugs than those who attended college.

The analysis is based on the 2007 National Healthcare Disparities Report, an examination of disparities in access to and quality of health care by race, ethnicity, income and education.

More information

The U.S. Food and Drug Administration has more about medications and older people.