AstraZeneca, the leading British drugmaker on Thursday reported that its core operating profit fell 16 percent year-on-year to 1.95 billion U.S. dollars in the first quarter of 2014, as marketing costs and research spending rose.

Global revenue rose 3 percent year-on-year at constant exchange rates, standing at 6.41 billion dollars in the first quater, the London-based company said in a statement.

Heart medicine Brilinta sales grew 94 percent to 99 million U.S. dollars, diabetes sales surged 106 percent to 347 million U.S. Dollars and respiratory sales up 12 percent to 1.27 billion U.S. dollars.

Emerging markets reported sales up 11 percent to 1.42 million dollars, with revenue in China rising 22 percent. The United States and Japan revenues grew 3 percent and 13 percent to 2.51 billion dollars and 537 million dollars respectively.

AstraZeneca also said research and development costs increased 13 percent to 1.2 billion dollars in the quarter. The company also reported it spent 2.7 billion dollars on sales, general and administrative affairs.

"The first quarter has seen continued momentum across the business and our revenue growth reflects the increasing contribution from the five growth platforms that showed strong performance," said Pascal Soriot, the chief executive officer of AstraZeneca.

"I am pleased with the significant progress we are making towards achieving scientific leadership in our core therapeutic areas," he added.

Recently, reports said U.S. pharmaceutical giant Pfizer was interested in acquiring AstraZeneca, and that the two companies were holding informal talks.