FRIDAY, Sept. 30 (HealthDay News) -- Prescription drug shortages in the United States, which reached a record high last year, are getting worse, the U.S. Food and Drug Administration said Friday.

So far this year, some 200 drug shortages have occurred compared to 178 in all of 2010, said Valerie Jensen, associate director of the Drug Shortage Program within the FDA's Center for Drug Evaluation and Research.

"This is real," said Dr. Jay Brooks, chairman of hematology/oncology at Ochsner Health System in Baton Rouge, La. "We've been down on this for several years. We have been able to manage around the issue here, but it is a very real issue and a very real problem."

Many of the scarce drugs are injectables, such as cytarabine and cisplatin, used to treat serious conditions such as cancer. Some are only given in hospitals and are "absolutely critical," said Jensen, who spoke at a Friday press conference.

More than half (54 percent) of shortages in 2010 were because of quality issues, such as sterility or drug impurities. Some were due to delays or manufacturing capacity problems, with 11 percent caused by discontinuation of a drug and 5 percent resulting from raw material shortages, Jensen said.

"In 2011, we're seeing the same trend, a very large number of quality product issues leading to shortages," she added.

Shortages also tend to occur in drugs that are not "economically attractive," said Jensen. This could mean that only one company produces the drug, making it harder to find alternatives if the supply dries up.

"A lot of it has to do with generic drugs," Brooks explained. "Few people make them. The margins are not very high."

The anesthetic propofol, which was implicated in Michael Jackson's death, for instance, sells for only 48 cents per 20 milliliter vial. A shortage of propofol in 2010 "was severe," said Jensen.

Some shortages are unforeseeable.

"There were several potential shortages due to the Japan earthquake," Jensen said. Several firms lost suppliers, but the FDA was able to quickly qualify other suppliers and avert any actual shortages, she said.

The FDA has very limited authority to combat shortages, and it cannot tell a company how much of a medication to produce. Although it requires sole producers of a drug to inform the agency if they're going to discontinue it, there is no penalty if firms don't report to the agency.

More information

For more on drug shortages, visit the U. S. Food and Drug Administration.