As the makers of EpiPen battle a firestorm surrounding price increases, a new federal lawsuit seeking class-action status argues that the company is engaging in price gouging by forcing consumers to buy the pens in packs of two.

The lawsuit was filed Tuesday in the Eastern District of Michigan on behalf of six EpiPen purchasers, three of them based in Michigan. It says there is little evidence doctors ever recommended the pens be sold in packs of two — and yet by 2011, EpiPen’s maker Mylan did just that.

The company emphasized the decision was for the safety of patients, yet continued to sell the pens one by one in other countries, the lawsuit says.

The lawsuit also claims that Mylan omitted facts about the effectiveness of a single dose of an EpiPen. By forcing people to buy two pens, the company’s behavior was “deceptive and unconscionable,” the lawsuit says.

“In short, (Mylan is) misstating the science of EpiPen dosage in order to purportedly justify its price gouging,” the lawsuit says.

The EpiPen is an epinephrine auto-injector used to treat allergic reactions. Its price has risen from $57 in 2007 to about $500 today, though many with health insurance pay a reduced price. There’s no generic equivalent, no brand-name competitor, and the drug expires annually, so schools and consumers have to keep replacing it.

In the wake of the most recent price hike that made news this month, the company announced it would offer coupons covering up to $300 “for patients in health plans who face higher out-of-pocket costs” and double the income level at which families are eligible for assistance in purchasing the medication to 400% of the federal poverty level.

That latest move has faced criticism from politicians and patient advocates, who describe the company’s actions as emblematic of the drug industry’s unfair stranglehold on the market for life-saving treatments.

“Really, Congress does need to do something to change this picture,” Marianne Udow-Phillips, director of the Center for Healthcare Research & Transformation at the University of Michigan, told USA TODAY. “This is a perfect demonstration of the complexity and real problems with pharmaceutical pricing in this country.”

Contact Daniel Bethencourt: [email protected] or on Twitter @_dbethencourt. USA TODAY contributed to this report.