WASHINGTON — Pharmaceutical executives, testifying before Congress, could not readily explain on Tuesday why the prices for many brand-name prescription drugs were much higher in the United States than in other developed countries.

“It is almost as if the taxpayer has ‘stupid’ written on their face,” Senator Bill Cassidy, Republican of Louisiana, told the seven executives, who faced a barrage of questions and criticism at a three-hour hearing of the Senate Finance Committee.

Mr. Cassidy joined two other Republican senators, Charles E. Grassley of Iowa and John Cornyn of Texas, and all the Democrats on the panel in expressing deep concern about constituents who could not afford the drugs they needed to survive.

Senator Robert Menendez, Democrat of New Jersey, the home to many drug and biotechnology companies, offered what he described as “a friendly warning” to the witnesses. “If you don’t take meaningful action to reduce prescription drug prices,” he said, “policymakers are going to do it for you.”