Shares of Biovail were among the best-performing health-related stocks Friday, rising 21% after the company said the Food and Drug Administration approved its Tramadol ER painkiller.

The painkiller was approved for the treatment of moderate to moderately severe chronic pain in 100 milligram, 200 milligram and 300 milligram dosage strengths. Biovail, it said, is the only company to submit an application to the FDA for review and to receive approval for the once-daily tramadol formulation. Biovail said it is already in negotiations with a marketing partner for the commercialization of Tramadol ER. Biovail expects to launch the product in early 2006. "The timing of the approval gives Biovail a significant competitive advantage and allows us to further diversify our revenue base," the company said. "The conditions of approval by the FDA for Tramadol ER support three years of exclusivity for the indication and doses approved." Shares were trading up $3.84 to $22.11.

Biogen Idec ( BIIB - Get Report) traded actively after the company said it would cut 17% of its workforce as part of a plan to reduce its cost structure. The job cuts, which should be completed by the end of the year, are expected to result in pretax charges of between $30 million and $40 million. Biogen also said that it plans to divest several non-core assets. As the divestitures occur, the company said, it will provide financial gain and loss information.

In all, the company said the actions taken should result in annual savings of $200 million to $300 million. "Biogen Idec expects that the increased economic flexibility will permit it to earmark approximately $200 million a year for business development and external research opportunities starting in 2006. By comparison, the company had earmarked approximately $50 million for business development in 2005," the company said. Shares were recently trading down 46 cents to $41.98 on volume of more than 5 million shares.

Shares of Martek Biosciences fell 10% after the company posted mixed third-quarter results and warned that fourth-quarter results would be below Wall Street forecasts. The company reported a third-quarter loss of $100,000, or break-even, on sales of $39.5 million. Analysts surveyed by Thomson First Call were expecting a bigger loss of 3 cents a share on slightly higher sales of $39.8 million. A year ago the company posted earnings of $5 million, or 16 cents a share, on sales of $47.3 million.

Looking ahead, Martek forecast fourth-quarter earnings of $2.9 million to $3.5 million, or 9 cents to 11 cents a share, on sales of $52 million to $53 million. Analysts had been expecting earnings of 12 cents a share on sales of $56.8 million. Shares were trading down $5.07 to $44.68.

Pain Therapeutics ( PTIE) rose 3% after the company said its Remoxy drug performed well in a phase III trial. The company said that Remoxy, an abuse-resistant form of long-acting oxycodone, met its primary endpoint of reducing pain in osteoarthritic patients who suffer from moderate-to-severe chronic pain. Remoxy demonstrated a statistically significant difference compared with a placebo, it said. Looking ahead, Pain Therapeutics said that it would conduct a phase III registration study that can support a new drug application under an FDA filing strategy known as 505(b)(2). The company expects to initiate the study by the end of 2005. Shares were trading up 17 cents to $6.70.

Other health care volume movers included Nektar Therapeutics ( NKTR - Get Report), up 66 cents to $19.80; Pfizer ( PFE - Get Report), down 16 cents to $26.35; Amgen ( AMGN), up $2.52 to $84.81; Bristol-Myers Squibb ( BMY), up 28 cents to $25.16; Merck ( MRK), down 12 cents to $29.07; Johnson & Johnson ( JNJ), up 59 cents to $64.69; and Schering-Plough , down 7 cents to $22.38.