BOSTON (AP) - The nation's largest drugstore chain has agreed to pay $200,000 and change some of its procedures after state investigators determined that multiple stores in Massachusetts failed to track the opioid use of some high-risk patients in the state's Medicaid program.

The Boston Globe reports Walgreens in a settlement filed on Wednesday agreed to update its policies and procedures and train staff to ensure pharmacists properly monitor such patients.

The state attorney general's office found that some Walgreens stores took cash for controlled substances from MassHealth patients instead of seeking approval from the agency. In many cases, MassHealth had rejected the prescription or wasn't billed.

A Walgreens spokesman says their records indicate the prescriptions in question were given to patients for genuine medical reasons and were issued by licensed practitioners.