Pfizer reported a first quarter net profit of two billion dollars, down 26% compared with the same three months last year.
The company said the drop -- which was broadly in line with market expectations -- was linked to costs from its October $68 billion buy-out of rival Wyeth.
The takeover created the world's biggest drug maker, but Pfizer said it also spelled higher taxes as well as an increase in interest payments from borrowing to fund the deal.
Since taking over Wyeth last year Pfizer has slashed 6,900 jobs as it aims to save billions in cost savings.
"The Company remains on-track to achieve the cost-reduction target of approximately $4-5 billion dollars, by the end of 2012," the company said on May 4.
The Wyeth purchase increased revenues by around 55% to $16.8 billion in the first quarter, including foreign exchange gains.
Pfizer makes Viagra for erectile dysfunction and Lipitor for cholesterol. Wyeth makes Centrum multivitamins and the popular Advil pain reliever.
Copyright Agence France-Presse, 2010