New York Health Commissioner Dr. Nirav Shah says the state's new online database of drug prescriptions has cut so-called "doctor shopping" by 75 percent.
The Internet System for Tracking Over-Prescribing, called I-STOP, began operating in August.
Health officials say more than 66,000 practitioners have used it more than seven million times already to check prescriptions on nearly three million patients.
Doctors, physician assistants and nurse practitioners are now required to check the database before prescribing painkillers, with pharmacists responsible for recording related prescriptions they fill.
The law is meant to help practitioners review patient drug histories through the health department's online registry.
Doctor shopping refers to patients getting drug prescriptions and supplies from multiple practitioners.
The department uses a threshold of five prescribers and five pharmacies over three months.