Dr. Theodore Koppanyi, 83, retired chairman of the pharmacology department of Georgetown University's medical and dental schools and an authority on drugs affecting the autonomic nervous system, died of an intestinal hemorrhage Jan. 22 at a hospital in Budapest.

Dr. Koppanyi joined Georgetown University as a professor and pharmacology department chairman in 1930. He stepped down as chairman in 1967 and continued to teach until returning to his native Hungary in 1970.

After coming to this country in 1923, he did research on the effects of barbiturates and developed tests for detecting their presence in the human body. He helped introduce analeptics to treat barbiturate poisoning. He also did extensive research work with the National Institutes of Health's National Heart Institute.

He attended the University of Budapest and earned his doctorate at the University of Vienna. While studying at those institutions, he was credited by many with discovering regeneration in the central nervous system.

He came to this country in 1923 and taught at the University of Chicago and at Syracuse and Cornell universities before joining the Georgetown faculty.

Dr. Koppanyi once told a reporter that "the task of pharmacology is to replace surgery. We should be able to do with drugs what surgeons accomplish with their knives."

He was the recipient of Georgetown University's 175th Anniversary Medal of Honor in 1964, and received a 1958 Fulbright Award. He was a past chairman of the Washington chapter of the Society for Experimental Biology and Medicine, a past vice president of the D.C. Academy of Medicine, a fellow of the American Association for the Advancement of Science, and a member of the Cosmos Club.

Dr. Koppanyi was the author of hundreds of technical works, including a history of pharmacology, and was coauthor of "Experimental Pharmocodynamics," a standard text in the field.

His marriage to the former Hermione Jane Bartels ended in divorce.

Survivors include his second wife, who lives in Budapest.