HIV patients are at risk for being prescribed wrong drug combinations
Research Activities, July 2010, No. 359
In the last 10 years, the number of antiretroviral medications used to treat HIV/AIDS has increased dramatically. With so many drugs and numerous combination therapy regimens now available, the risk of prescribing errors has risen. Agency for Healthcare Research and Quality (AHRQ) researchers Fred J. Hellinger, Ph.D., and William E. Encinosa, Ph.D., have found that patients with HIV disease in 2005 were three times as likely to experience wrong drug combinations compared with 1999 and 2000. They used commercially available inpatient, outpatient, physician, and prescription drug claims data to study two time periods: 1999-2000 and 2005. By 2005, physicians were using the common practice of boosting, whereby a drug in the protease inhibitor (PI) class would be combined with low-dose ritonavir (another PI) to increase its effectiveness. The researchers focused on claims for HIV drug combinations not recommended by the U.S. Department of Health and Human Services Panel on Antiretroviral Guidelines for Adults and Adolescents.
During 1999-2000, giving a PI with the lipid-lowering drug simvastatin was the most common prescribing error, occurring in 1 percent of all patients. Giving these two drugs together can cause an increased risk for muscle problems caused by simvastatin. By 2005, this type of prescribing error had decreased to only 0.4 percent of patients, and the most common error was that of receiving particular protease inhibitors without the boosting agent ritonavir. This occurred in 5.3 percent of patients. In 1999 or 2000, the risk of an inappropriate drug combination was 1.9 percent. By 2005, this had increased to 5.9 percent.
These findings underscore the vigilance physicians now need to use when it comes to prescribing combination antiretroviral therapy and selecting appropriate drugs to use together. The goal is to minimize adverse reactions while maximizing the potential to control HIV disease progression.
More details are in "The cost and incidence of prescribing errors among privately insured HIV patients," by Drs. Hellinger and Encinosa, in the 2010 Pharmacoeconomics 28(1), pp. 23-34. Reprints (AHRQ Publication No. 10-R044) are available from the AHRQ Publications Clearinghouse.