The Dow Jones index rose on Tuesday.
However, the S&P was little changed and the Nasdaq fell as financial and technology shares declined after leading a recent rally.
Shares of Pfizer rose 5.5$ to $US14.93, after positive comments from analysts at Credit Suisse First Boston following a meeting with the drug company's management.
Merck gained 2.4% to $US24.98.
Energy shares were also up as US crude oil futures briefly touched $US60 per barrel before settling up 35 cents at $US58.85. Exxon Mobil Corp rose 2.2% to $US70.82.
Coca-Cola rose 3.9% to $US44.40 as consumer staples also benefited from a move into defensive stocks.
Apple Inc lost 4% to $US124.42.
In economic news, data showed the US trade gap widened in March for the first time in eight months, signaling weak overseas demand.
The Dow Jones industrial average rose 50.34 points, or 0.6%, to 8,469.11.
Standard & Poor's 500 Index was off 0.89 points, or 0.1%, to 908.35. The Nasdaq Composite Index was down 15.32 points, or 0.88%, at 1,715.92.
Trading was active on the New York Stock Exchange, with about 1.61 billion shares changing hands - above last year's estimated daily average of 1.49 billion.
About 2.53 billion shares were traded on the Nasdaq - above last year's daily average of 2.28 billion.
