Pharmaceutical industry ad spend fell 18.4% in 2008 to $4.3 billion in the US, according to The Nielsen Company. Johnson & Johnson, the sole drug company among the nation’s top 10 advertisers, spent $1.2 billion on advertising – a drop of 5.4% from 2007 spend.

Overall, US ad spend declined 2.6% for the year to $136 billion, and the top 10 advertisers collectively spent 15% less than in 2007. Of the top 10 advertising sectors, the drug industry, ranked second in spending, posted the largest drop in spend, followed by the top-spending automotive industry’s 15.5% cutback and an 11.4% drop in ad spend for motion pictures. Fast food was the only segment to boost spending, by 3.8%. Wal-Mart, the 19th biggest spending company, upped its advertising by a whopping 55%.

Proctor & Gamble remains the nation’s top advertiser, despite having spent 19.3% less in 2008, Nielsen said.