The two companies had agreed in 1996 to co-promote Lipitor, a drug analysts predict could have worldwide sales of about $5 billion next year.
But Robert H. Uhl, a drug analyst at Salomon Brothers, said sales would "start heading downward again next year."
That firm's drug analyst maintained her buy rating after the meeting, but the next day several of the firm's portfolio managers sold, the S.E.C. said.
"Everybody bloodied themselves," said David Saks, a drug analyst at Gruntal & Company.
"It was a good quarter, they beat my estimate," said Joyce Albers, a drug analyst at First Boston.
"They are in real trouble and need money to rescue them," said Jerry Treppel, a drug analyst with Dillon, Read & Company.
But drug analysts estimate that as many as 10 percent of all American physicians now sell medicines.
"Agriculture is, by its nature, an unpredictable business," said Neil Sweig, a drug analyst with Ryan, Beck & Company.
The company "will have an opportunity on Friday to clear the air," said Barbara Ryan, a drug analyst with Prudential Securities.
But Hemant K. Shah, an independent drug analyst, said he was doubtful that retail pharmacies would be able to lower prices.