The Senate Finance Committee announced they have opened an inquiry that will look at financial ties between prescription painkiller manufacturers and pain experts, patient advocacy groups and bodies that set guidelines on physicians’ use of the medications.

The New York Times reports the committee wants to ensure that doctors and patients are receiving accurate information about the risks and benefits of painkillers, without regard to the financial interests of drug manufacturers.

The committee is also seeking information from several academic experts about their links to drug makers.

Companies involved in the inquiry are Purdue Pharma, which makes OxyContin, Endo Pharmaceuticals, which makes Percocet, and Johnson & Johnson, maker of Duragesic. The American Pain Foundation, a patient advocacy group, and the Pain and Policy Studies Group at the University of Wisconsin, also received letters from the committee.