"It's something I hear about everywhere I go," Clinton said.
Biotech stocks reacted to Hillary's tweet Monday, dropping by more than 4 percent industrywide.
Later in the day, a Capitol Hill source said that Rep. Elijah Cummings, D-Md., is planning to request information about Daraprim's "astronomical price increase" from drug's new owner, Turing Pharmaceuticals. Cummings has been conducting an investigation of recent drug price increases.
Sanford Bernstein analyst Ronny Gal said that if Clinton wins the White House, "I would say" that drug prices will take a hit.
"The entire argument that the government will begin to behave [as controller of prescription prices] is something the drug industry has been fighting tooth and nail," Gal said. "If that actually becomes a policy and looks like it's coming to a chance of passing you'll see drug company valuations cut 20 percent across the board."
Before Clinton tweeted her reaction to the news about Daraprim, Dr. Scott Gottlieb of the American Enterprise Institute said that a New York Times story about the drug's price hike comes a time where there already was "a lot of negative sentiment" about drug prices, and that "the industry is vulnerable" to those public feelings.
Earlier this month, the Kaiser Family Foundation said a survey had found that 72 percent of the public considered drug prices unreasonable. And Clinton's leading challenger for the Democratic presidential nomination, Sen. Bernie Sanders of Vermont, has already introduced a plan to deal with drug prices, which includes allowing Medicare to negotiate prices with pharmaceutical companies and allowing people to import drugs from Canada, where medication is less expensive.
Gottlieb said "anecdotes like" the huge price increase of Daraprim "hurt and can help drive bad legislation, and Clinton is sure to propose a basket of Obamacare 'fixes' this week that will include populist calls for drug price controls."
"The problem is that there is more anti-industry populism on both sides of the political divide now. I still don't think the votes are there to get anything through the House [of Representative] but the industry is very vulnerable to things like Medicaid 'best price,' " Gottlieb said. Medicaid's best price program is a rebate scheme that helps lower federal and state costs for covering prescription drug purchases for Medicaid enrollees.
"Ultimately anything that would extend drug price controls would have to come as a pay for on broader legislation that gave Republicans something in return. But I do think the drug industry should be much more worried than they are that they could be on the receiving end of adverse legislation."