Spending was not disclosed. The OTC version of the drug is expected to hit shelves later this year.
Schering-Plough prescription drug Clarinex, successor to Claritin, is handled by WPP's CommonHealth Quantum Group, Parsippany, N.J.
A Schering-Plough spokesman and an Ogilvy executive declined to comment.
The marketer is based in Kenilworth, N.J.