An agreement reached yesterday by local leaders and drug rehabilitation centers in Gramercy Park will put constraints on recovering heroin addicts who loiter or commit crimes in the neighborhood, the Manhattan district attorney’s office said.

The deal will require the neighborhood’s four methadone clinics, which serve 1,950 patients, to refuse treatment to patients who are arrested once or caught loitering multiple times in the neighborhood, the program director from the district attorney’s office, Leroy Frazier, said

The clinics will work with the three police precincts that cover the area between East 14th and 28th streets to enforce the measure, the district attorney’s office said.

The president of the Flatiron/ 23rd Street Partnership, Jennifer Brown, who lobbied for the agreement, said some patients from the clinics come to the neighborhood and conduct illegal activities on a daily basis.

Gramercy Park is one of many neighborhoods in the city negatively affected by methadone patients, the chairman of the anthropology department at John Jay College of Criminal Justice and an expert on heroin use in New York, Richard Curtis, said.

However, other neighborhoods are less likely to come to such an agreement, as they lack the financial clout of Gramercy Park, Mr. Curtis said.

In 2004, the Manhattan district attorney’s office reached a similar agreement with 12 methadone clinics that serve about 8,000 patients a day near 125th Street in Harlem, Mr. Frazier said. One hundred twenty patients were displaced following arrests in the surrounding area, the bulk of which occurred in the first two years of the program.

Fewer arrests have been made recently because patients have seen that the clinics are serious about the rules, Mr. Frazier said.