Dr. Arthur Hull Hayes Jr., commissioner of the Food and Drug Administration, yesterday said the Reagan administration is considering requiring the salt content of food to be shown on containers.

He also criticized doctors for the "frequent and inappropriate use" of prescription drugs, on which he said there are "shocking statistics on adverse reactions." He said education rather than government regulations is the solution to this proglrm, however, and he was challenged to counter drug manufacturers' advertising of the popular tranquilzer Valium.

The food industry is being asked for ways to reduce the sodium content of processed foods, Hayes told the Washington Press Club. Hayes and Health and Human Services Secretary Richard S. Schweiker are to meet with about 200 industry representatives on June 30.

About 50 million Americans suffer from hypertension (high blood pressure), which is often caused by too much sodium in the diet.

The Reagan appointee first voiced his criticism of doctors on drugs in 1975, when he was a clinical pharmacologist at Pennsylvania State University's Hershey Medical Center.

"I'm afraid the situation is the same," he said yesterday. But instead of more government regulation, he said, the FDA will rely on physician and patient education as the best way toward change.

There will in fact be a cutback, he said, in new regulatory initiatives and major new programs. And he is not ready, he said, to order "patient package inserts" -- pamphlets that warn of drug dangers -- in several more drugs.

The Public Citizen Health Research Group urged the FDA to halt medical journal ads praising Valium as highly "safe and effective . . . when prescribed judiciously and used wisely."

Dr. Sidney Wolfe, health group director, called the ads "a desperate attempt to regain lost business" by Roche Laboratories, Valium's manufacturer.

For several years Valium has been the No. 1 prescription drug in sales, according to several counts. Publicity about adverse reactions and overdoses, however, cut prescriptions from 61.9 million in 1975 to 33.9 million last year.

The health group said Valium is not always safe, even at recommended dosages, and in some persons may cause "an inexorable progression from low to high dosage." It asked Hayes to order corrective ads to counter "false and misleading" statements.