Eli Lilly has revealed a 7% drop in profits following falling sales of its Prozac anti-depressant drug.
The company posted third quarter earnings of £500 million, or 66 cents per share, compared with £540m, or 71 cents, the year-earlier quarter.
Eli Lilly lost its exclusive US Prozac marketing rights in August, and has since faced competition with cheaper copycat drugs.
The company also suffered from costs that rose faster than revenues.
Sales costs rose 12%, marketing and administration gained 11.8% and research and development increased 8.2%.
Revenues rose 2.2% to £1.98bn.
In the third quarter, sales of its schizophrenia treatment Zyprexa and the osteoporosis drug Evista, helped boost revenues.
Sales growth, without Prozac, was 15% in the third quarter, but gross margins as a percent of sales fell by 1.7%, to 80.9%, due primarily to the decrease in Prozac sales.