Thin pipelines and a loss of patent protection is hurting big drugs firms
US drugs giant Pfizer posted an 18% drop in profits for the first three months of 2008 after competition from cheaper patent free products.
The New York-based firm's net income fell to $2.78bn (£1.4bn), from $3.39bn in the January to March period.
It blamed the loss of US patent protection to sell blockbuster blood-pressure drug Norvasc and allergy relief medicine Zyrtec.
The loss of exclusivity for key drugs is a concern across the sector.
Pfizer also nursed a worse-than-expected sales decline of flagship cholesterol fighter Lipitor, which generated $300m less revenue than some analysts were expecting.
It insisted that it would meet its previously stated profit targets for the year, helped by a massive cost-cutting programme that has already seen 10,000 jobs go.
The firm's poor performance came despite a boost from the weak dollar which makes sales abroad more valuable.
Shares in the company dropped 3.3% to $20.4, topping the losers on the benchmark Dow Jones index, which closed virtually unchanged in New York, up 1.2 points.