HARTFORD, Conn. - Connecticut Attorney General Richard Blumenthal is suing the federal government because, he says, it does not adequately warn consumers of the side effects of controversial painkiller OxyContin.

The drug has been the subject of a civil suits by several state attorneys general and a federal criminal investigation that resulted in $634.5 million in fines for manufacturer Purdue Pharma.

The drug's propensity for causing addicts has been the issue, and Blumenthal thinks the Food and Drug Administration has not taken enough action. He filed his action in federal court Monday.

"The FDA is disregarding dangers of adverse reactions and side effects, as well as abuse and addiction, by failing to require stronger black box warnings or issue a safety alert of public health advisory," Blumenthal said.

"The FDA has a legal and moral responsibility to ensure that providers and patients fully understand the potential dangers of improperly prescribing OxyContin. Inaction by the FDA is completely inexplicable and unacceptable when public health and safety are clearly at risk."

Blumenthal admitted the drug has positive effects when used properly but also says internal documents from Purdue Pharma showed many physicians did not understand OxyContin's controlled release delivery system and were inappropriately prescribing it.

Blumenthal petitioned the FDA four years ago, and warned the FDA to stop ignoring it last July. His complaint asks that the FDA's failure to act be declared unlawful and that the FDA issue a decision on it 30 days after the declaration.

Purdue Pharma paid $20 million to 27 state attorneys general last May, and then-Kentucky Attorney General Greg Stumbo hired a campaign contributor to file his own suit in October.

Purdue Pharma's $10 million settlement with West Virginia Attorney General Darrell McGraw has caused great debate among McGraw, state lawmakers and the federal Centers for Medicare and Medicaid Services.