State pharmacy regulators have opened an investigation into reports that CVS Caremark Corp. refilled prescriptions and billed insurance companies without patients' consent.

Virginia Herold, executive officer of the California Board of Pharmacy, said Tuesday that investigators were probing complaints about the refill practices of the country's largest drugstore chain after Walgreen Co.

Herold said the complaints concerning "CVS and refills" were similar to allegations raised in four Los Angeles Times reports published in the last three months. 

Customers in California and other states said they were surprised to find that CVS had renewed doctors' prescriptions and billed insurers without their consent and, in some cases, enrolled them in an automatic refill service without their knowledge, according to Times columns. 

CVS policy requires that a patient's consent "be obtained before a prescription is filled," said Michael DeAngelis, a spokesman for the Woonsocket, R.I., company. CVS, he said, would provide the pharmacy board with any information needed. 

The state board is the third government body known to be looking into the company's refill practices. (MORE)