RCW 69.41.160: Pharmacy signs as to substitution for prescribed drugs.

Every pharmacy shall post a sign in a location at the prescription counter that is readily visible to patrons stating, "Under Washington law, a less expensive interchangeable biological product or equivalent drug may in some cases be substituted for the drug prescribed by your doctor. Such substitution, however, may only be made with the consent of your doctor. Please consult your pharmacist or physician for more information."