World number one advertiser Procter & Gamble is readying a $100 million (€91.0m; £63.2m) US promotional blitz to back a new heartburn medicine.

The consumer goods colossus is throwing its marketing muscle behind Prilosec, a drug that recently gained regulatory approval to switch from prescription to over-the-counter status. P&G has a three-year exclusive distribution agreement with the remedy’s manufacturer, AstraZeneca.

Prilosec hits stores September 15. Chains such as Wal-Mart and Costco are already advertising its imminent arrival in their outlets, while P&G has sent samples to thousands of Americans who put their names down during a promotional tour of 24 cities.

After the drug is launched, an advertising barrage will commence, involving TV, radio and print spots.

P&G’s chief weapon, however, is price. The group hopes the low cost of Prilosec compared with prescription heartburn remedies will help it triumph in an already crowded market.

P&G has high hopes for the drug – it is expecting first-year sales of up to $400m.

Data sourced from: USA Today; additional content by WARC staff