Four out of five drugs approved for sale in 2008 were tested in foreign countries, according to a new federal report that raises alarms about the Food and Drug Administration’s ability to regulate drug trials abroad.

The report, authored by the inspector general of the  Department of Health and Human Services, says that ten medicines approved in 2008 were tested entirely abroad without one subject in the United States.

The majority of clinical trial sites were in Western Europe, where ethical regulations are just as robust as American rules, but 26 percent of all subjects were enrolled in Central and South America, where there is generally less regulation, the New York Times reports.

Pharmaceutical companies seeking approval for new drugs conduct clinical trials with human subjects to assess the safety and effectiveness of the products.

“As sponsors increase the number of foreign clinical trials in support of F.D.A. marketing applications, the agency’s current method of using inspections to ensure human subject protections and data validity is becoming increasingly strained,” wrote Daniel R. Levinson, the inspector general.

Levinson said the FDA is often unaware of foreign clinical trials being conducted until after they are done, and can only go back to trial sites after a company submits an application to sell the medicine in the United States—which can be years after the trial.

The inspector general also found that the FDA was 16 times more likely to audit a domestic trial than to audit a foreign one, which can cost as much as $40,000. He faulted the agency for sometimes having incomplete clinical trial records, and encouraged the agency to adopt a standardized electronic format.

The report “highlights a very frightening and appalling situation,” said Rep. Rosa DeLauro (D-Ct.). “By pursuing clinical trials in foreign countries with lower standards and where FDA  lacks oversight, the industry is seeking the path of least resistance toward lower costs and higher profits to the detriment of public health.”

In written comments, the FDA said it was developing procedures to address Levinson’s recommendations, including testing a new computer system to monitor clinical trials abroad.