PHILADELPHIA — A Pennsylvania law restricting methadone clinics within 500 feet of parks, places of worship and residential neighborhoods violates the federal Americans with Disabilities Act, a federal appeals court ruled.

Methadone is a synthetic narcotic used to treat heroin and opium addicts.

The lawsuit was brought on behalf of a Reading clinic that wanted to open a new location, but was unable to do so because state law required City Council approval of clinics in the restricted zones. A lower court dismissed the lawsuit, but the 3rd U.S. Circuit Court of Appeals ruled Friday that the state law was discriminating against those with the disability of heroin addiction.

The plaintiffs' lawyers, Barbara E. Ransom and Michael Churchill of the Public Interest Law Center of Philadelphia, said the case will have an impact statewide. At the beginning of June, the city of Dubois in Clearfield County had rejected a methadone clinic under the same state law, Ransom and Churchill said.