Federal health officials have decided to name new chiefs to step up the government's efforts to fight alcholism and drug abuse.

Health, Education and Welfare Secretary Joseph A. Califano Jr. and his chief deputy for mental health, drug and alochol programs, Dr. Gerald Klerman, last week fired Dr. Ernest P. Noble, head of the National Institute on Alcohol Abuse and Alcoholism.

Several weeks ago, Klerman told Dr. Robert L. DuPont, head of the National Institute on Drug Abuse, to look for a new job.

Last December, at Califano's orders Klerman fired Dr. Bertram S. Brown, longtime head of the National Institute of Mental Health. That leaves all three branches of HEW's Alcohol, Drug Abuse and Mental Health Administration (ADAMHA) with acting chiefs.

Many federal health officials are privately accusing Califano of distrupting these medical institutes by becoming the first HEW secretary to make wholesale replacements of traditionally nonpolitical heads.

Califano pledged on taking office not to "politicize" the National Institutes of Health by making political changes in its institute directors. But he said nothing about the alcohol, drug abuse and mental health institutes, which are not part of NIH, though they are much like disease-fighting units.

Informed health officials said Klerman told DuPont that Califano is determined to have "new blood" in top posts.

"There are new initiatives coming" in both alcoholism and drug abuse, and "we feel they'll best be handled by new leadership," Klerman said. Also, he said, he wants to exert more leadership as ADAMHA chief, since "all these fields are linked."

For example, he said, "there are the teen-age problems. Teen-age drinking drug abuse and pregnancy are all up, and we have to link our efforts to control them."

Delegates to a National Drug Abuse Conference in Seattle - workers in prevention, research and treatment - last month urged Califano to keep DuPont, citing his "professional expertise," "commitment" and "effective leadership."

DuPont was hero in the early 1970s of a District of Columbia war against heroin. Then president Nixon chose him to head both a temporary White House Special Action office for Drug Abuse Prevention and the new institute.

DuPont said he has "no plans to leave," but added, "I've been considering alternatives" and I don't plan to stay for a prolonged period." Both he and Klerman confirmed that Klerman suggested that his stay should be limited.