"Drug disasters are literally built into the current system of drug testing and approvals in the United States. Recent changes in the system have only increased the proportion of new drugs with serious risks," said Donald Light, the sociologist who authored the study and a professor of comparative health policy at the University of Medicine and Dentistry of New Jersey.
According to a 1999 report for the Institute of Medicine, adverse drug reactions (ADRs) can occur for a number of reasons, including improper prescribed dosage, drug abuse and drug interactions.
This study has found the organizational basis of patient risk from prescription drugs, and suggests institutional reforms to help avoid or reduce future drug disasters.
Lights said that the existing testing system evaluates the effectiveness of new drugs based on their effects compared to placebos, instead of using current approved drugs as benchmarks of efficacy.
Systematic reviews indicate that one in seven new drugs is superior to existing drugs, but two in every seven new drugs result in side effects serious enough for action by the U.S. Food and Drug Administration (FDA), including black box warnings, adverse reaction warnings, or even withdrawal of the drug.
This made Light to say that new drugs are twice as likely to harm patients as to provide them with benefits superior to existing drugs.
Light's analysis suggests another flaw lies within the design of clinical trials, as they are conceptualized with an aim to minimize evidence of toxic side effects. For this pharmaceutical companies sample from a healthier population atypical of patients who will actually take the drug, excluding people who are older, poorer or who have multiple health problems.
Trials are run long enough to pick up main effects but not to detect some long term side effects. As approvals are based on these data, thus drugs with harmful effects sometimes get through.
"Based on our current system, the designation of 'safe and effective' on today's new drugs could be replaced with, 'apparently safe based on incomplete information, and more effective than a placebo,'" said Light.
The study will be presented at the annual meeting of the American Sociological Association (ASA).