Updated from 3:28 p.m. EDT

Shares of

Alpharma

(ALO) - Get Report

were among the best-performing health-related stocks Friday, rising 7.8% after the company posted first-quarter earnings that were ahead of expectations.

Excluding items, the generic drugmaker posted earnings of $19.3 million, or 37 cents a share, on sales of $378.1 million. Analysts polled by Thomson First Call were expecting earnings of 28 cents a share on sales of $378.2 million. A year ago the company earned $2.5 million, or 5 cents a share, on sales of $311.7 million. The strong year-over-year sales gains were attributed to higher generic pharmaceuticals business, which benefited from the launches of gabapentin capsules and tablets during the fourth quarter of 2004.

Despite the upbeat gabapentin sales news, the company said its U.S. generics business continues to face significant challenges. Looking ahead, Alpharma reiterated its 2005 earnings outlook, saying that it continues to believe 2005 results will not exceed 2004 levels. Results for 2005 will be affected by continued weakness in the company's U.S. generics business, it said, and by an absence of a benefit for U.S. tax losses in the consolidated tax provision. Shares traded up 79 cents to $10.89.

Harvard Bioscience

(HBIO) - Get Report

fell 9.3% after the company posted first-quarter results that fell below expectations. The company posted adjusted earnings of $806,000, or 3 cents a share, on sales of $22.4 million. Analysts were expecting earnings of 5 cents a share on sales of $23.4 million. A year ago the company earned $798,000, or 3 cents a share, on sales of $22.2 million. Despite the first-quarter shortfall, the company backed its 2005 earnings and sales guidance. In March the company said that it would post adjusted 2005 earnings of 22 cents to 26 cents a share on sales of $95 million to $100 million. Analysts are expecting earnings of 24 cents a share on sales of $99 million. Shares traded down 36 cents to $3.52.

Shares of

Watson Pharmaceuticals

(WPI)

fell 1.9% after the company posted mixed first-quarter results and cautioned investors that 2005 earnings would fall to the low end of its previous guidance. In the latest period, the company earned $33.9 million, or 33 cents a share, on sales of $400.8 million. Analysts were expecting earnings of 32 cents a share on sales of $412.9 million. A year ago the company earned $46.7 million, or 39 cents a share, on sales of $409.7 million. Looking ahead, Watson backed its sales guidance of $1.65 billion to $1.7 billion, but said that earnings would fall to the low end of its previous guidance of $1.33 to $1.43 a share. Analysts are expecting earnings of $1.37 a share on sales of $1.68 billion. Shares traded down 56 cents to $29.34.

Icos

(ICOS)

fell 4.7% after the company posted first-quarter results that were below expectations The company posted a loss of $46.4 million, or 73 cents a share, on sales of $13.8 million. Analysts were expecting a smaller loss of 67 cents a share on sales of $16.9 million. A year ago the company reported a loss of $86.3 million, or $1.36 a share, on sales of $16.5 million. Looking ahead, Icos forecast a second-quarter loss of $21 million to $30 million, or 33 cents to 47 cents a share. Analysts are expecting a loss of 33 cents a share. Shares traded down $1.06 to $21.57.

Other health care volume movers included

Pfizer

TheStreet Recommends

(PFE) - Get Report

, down 24 cents to $27.61;

Elan

(ELN)

, down 1 cent to $6.23;

Merck

(MRK) - Get Report

, down 59 cents to $34.16;

Amgen

(AMGN) - Get Report

, down 24 cents to $58.59;

Schering-Plough

(SGP)

, down 18 cents to $20.62;

Johnson & Johnson

(JNJ) - Get Report

, down 30 cents to $68.21; and

Genentech

(DNA)

, up 13 cents to $73.12.58.