A state law that authorizes the direct purchase of mail-order drugs from certain foreign pharmacies took effect Wednesday in Maine. "If Maine can do this, other states will do this. It could have a big impact on pharmaceutical companies' long-term profits and desire to invent new medications," Boston University professor Laurence Kotlikoff said. PhRMA has challenged the law in the U.S. District Court in Portland, Maine, the group's first lawsuit against a state over the importation of drugs. Residents could be exposed to counterfeit or tainted drugs, drugmakers have said.