Generic competition is continuing to eat into AstraZeneca's performance, but chief executive Pascal Soriot is still predicting a faster return to growth than expected.

The Anglo-Swedish drug giant booked fourth-quarter revenues of $6.84 billion, down 4% at constant exchange rates (CER) or 6% on an actual basis, as the firm continued to struggle with patent exclusivity losses and negative currency effects. 

Dragging down the books were sales of: Crestor (rosuvastatin), sliding 8% at $1.46 billion; Nexium (esomeprazole), which slipped 3% to $991 million; Seroquel (quetiapine), falling 22% to $372 million; Atacand (candesartan), down 33% at $134 million; and Arimidex (anastrozole), falling 23% to $86 million.

On a brighter note, AZ's key growth platforms contributed $190 million in revenue growth on a CER basis, an increase of 6% compared with last year.

Growth drivers for the period include: Symbicort (budesonide and formoterol), up 11% at $976 million; Brilanta (ticagrelor), up 139% at $92 million; Flumist, up 56% at $50 million; and Faslodex (fulvestrant) climbing 6% to $182 million.

However, the rises were more than offset by the declines, which, alongside continued investment in growth platforms and the enlarged late-stage pipeline, helped pull core operating profit down 26% to $1.98 billion.

Looking forward, AZ said it expects a low-to-mid single digit percentage decline in revenue at CER for 2014. 

Commenting on the results, Soriot said: "As expected, our financial performance for 2013 reflects the ongoing impact from the loss of exclusivity for several key brands. In the near term these headwinds will remain challenging, however I am confident that we can return to growth faster than anticipated and expect our 2017 revenues will be broadly in line with 2013".