Last June, approval was given to Mylan Pharmaceuticals for 10 and 20 mg omeprazole delayed-release capsules, as well as tentative approval for the 40 mg strength. Omeprazole is the generic version of AstraZeneca LP's Prilosec.

Blue Cross and Blue Shield of North Carolina switched to Prolosec when it became available in over-the-counter form in 2003. It sent members identified as frequent sufferers of intermittent heartburn coupons worth $10 off the retail purchase price of Prilosec OTC.

More than 40,000 coupons went to members who had filled a prescription for Prilosec or its generic form - omeprazole - within the past year.

Because benefits exclude medications available over-the-counter, the company were no longer cover Prilosec or omeprazole.

The successor medicine to Prilosec - Nexium - continued to be covered, but moved from Tier 2 to Tier 3.

Ever since it was first made available in September 2003, Prilosec OTC has become one of the leading over-the-counter remedies for treating frequent heartburn. Prilosec OTC contains the same active component (omeprazole) as prescription Prilosec.

Some health professionals have questioned whether consumers will use the over-the-counter product as intended. But research published in the journal Clinical Gastroenterology and Hepatology shows that frequent heartburn sufferers are able to follow and comply with the directions on the package label.

"A substantial majority of people who purchased Prilosec OTC complied very well with the label instructions" said Mark Fendrick, M.D., the University of Michigan professor who led the evaluation of this study. "And, contrary to some concerns that Prilosec OTC would result in decreased physician visits, this study showed that frequent heartburn sufferers actually increased consultation with their physicians."