MCLEAN, Va., Feb. 12, 2013 /PRNewswire/ -- Every person taking a prescription drug should be able to trust that the recommended dose is safe. This may not always be the case according to Dr. Dorothy L. Smith, President and CEO of Consumer Health Information Corporation. In the last ten years, many patients have developed unexpected toxicities from prescription drugs that have been on the market for 5-10 years. FDA has responded by cutting the doses of several drugs in half and withdrawing others. During this same time period, patient adherence in the general population has been increasing due to media attention and improved patient education by health professionals.
"Why have there been so many unexpected toxicities in the last 10 years after these drugs have been approved? Why are approved doses later being cut in half? Could there be a link to patient adherence?" To try to answer these questions, Dr. Smith reviewed the last 20 years of the patient adherence research in clinical trials. The findings were shocking:
- Between 1997-1999, patient adherence was not monitored in 53% of clinical trials. Many of these drugs are still on the market.
- Up to 30% of study patients do not take the full dose of the study drug.
- Study patients cannot understand 35% - 94% of Informed Consent documents.
- At least 50% of study patients do not tell the study team they missed doses.
- Many study patients do not realize that missing doses could endanger the lives of millions of people after the drug is approved.
- Poor patient adherence that is undetected in clinical trials may result in a dose that is inaccurate and too high.
Unexpected adverse drug reactions and toxicity could occur when patients in the general population are more adherent than those in the clinical trial. Dr. Smith urged clinical trial investigators to: