FILE - A sign marks a CVS branch on Tuesday, May 16, 2023, in Pasadena, Calif. (AP Photo/Marcio Jose Sanchez, File)(Associated Press) – CVS Health CEO Karen Lynch has stepped down with company shares sinking 19% this year and the health care giant struggling on several fronts. Company shares tumbled again Friday after CVS Health also warned of disappointing third-quarter earnings and said investors should not rely on guidance it laid out in August. Lynch will be replaced by veteran CVS Health executive David Joyner, who will attempt to steer the company through rising costs to its health insurance business, slumping drugstore sales and growing investor pressure. The company has already cut its forecast several times this year.