The Supreme Court of Iowa handed Schwarz Pharma Inc. and Pfizer Inc. a win on Friday, affirming that the companies don’t have to face claims from a woman who took a generic version of Schwarz’s brand name drug Reglan. The woman’s lawyers had argued that her claims against the brand drugmakers should be reinstated under a theory known as innovator liability, but the court called such an approach a “slippery slope.”

“We are unwilling to make brand manufacturers the de facto insurers for competing generic manufacturers,” Iowa Supreme Court Justice Thomas Waterman wrote in Friday’s 91-page decision.