Updated from 2:50 p.m. EDT

Alpharma

(ALO) - Get Report

shares fell 6% Friday as the company continued to spar with

Pfizer

(PFE) - Get Report

over the sale of a generic form of the epilepsy treatment Neurontin. Alpharma said Friday it had shipped three formulations of its drug to wholesalers, even as it and Pfizer await a court ruling on a patent suit that could end up blocking the sales. Alpharma's shares fell because Pfizer itself is now threatening to sell a generic form of the drug, too. The stock traded down $1.10 to $17.12.

Biovail

(BVF)

rose 4.1% after the company named Douglas Squires as chief executive officer. Squires will replace Eugene Melnyk, who will step down and remain chairman. Squires most recently served as president and CEO of MDS Pharma Services. Shares traded up 77 cents to $19.36.

Shares of

American Healthways

(AMHC)

traded actively Friday after the company posted in-line, fourth-quarter earnings and forecast 2005 sales above expectations. The health care provider earned 27 cents a share during the third quarter on sales of $71.9 million. Analysts polled by Thomson First Call were expecting earnings of 27 cents a share on sales of $77 million. Looking ahead, the company expects 2005 earnings of $1 to $1.02 a share, in line with estimates, on sales of $319 million to $331 million, which is higher than analysts' forecasts of $310.7 million. Shares traded down 7 cents to $27.38 on more than four times American Healthways' normal daily volume.

Zoll Medical

(ZOLL)

fell 6.6% after the company warned that fourth-quarter earnings would fall well short of expectations. The medical-device maker expects earnings of 23 cents to 28 cents a share on sales of $55 million. Analysts had been expecting earnings of 43 cents a share on sales of $57.4 million. Zoll blamed the shortfall on its inability to book $2.5 million in additional orders during the quarter, which was caused by unexpected unit configurations. Zoll traded down $2.26 to $31.99.

Other health care volume movers included

Merck

(MRK) - Get Report

, down 63 cents to $30.35;

Elan

(ELN)

, down $1.39 to $21.71;

Schering-Plough

(SGP)

, down 42 cents to $17.56;

Johnson & Johnson

(JNJ) - Get Report

, down 60 cents to $55.32; and

Genentech

(DNA)

, down 30 cents to $47.25.