The Food and Drug Administration ordered the removal of about 500 prescription cold, cough and allergy medications that have never received government approval for safety and effectiveness.
Pharmaceutical companies must discontinue manufacturing the drugs within 90 days and stop shipping them within 180 days.
"We have some specific safety concerns with some of them," Deb Autor, head of the FDA's Office of Compliance in the Center for Drug Evaluation and Research, told reporters in a telephone news conference. Autor said the problem is "what we do not know."
"We do not know if they are safe. We do not know if they are effective. We do not know if they are of adequate quality; and we believe that poses an untenable risk to consumers," she said.
Some medications marketed as "suitable for infants and children" contain ingredients listed in a 2008 FDA advisory warning against using over-the-counter drugs for children under age two. Others contain potentially dangerous combinations of ingredients. Some of the time-released prescriptions, which are supposed to work over eight to 12 hours, may deliver the full does within 30 minutes, Autor said.
Many of the drugs came on the market prior to a 1962 law requiring pharmaceutical companies to prove the product's effectiveness.
One pharmacist said a lot of the drugs on the FDA's latest list were already off the market.
"A lot of these medications have been discontinued. They're no longer available," Sophia DeMonte said on behalf of the American Pharmacists Association.
The list does not include over-the-counter medications.
For the complete list of unapproved medications visit the FDA's website.