Pharmaceutical firms added to uncertainty in their industry on Thursday after Astrazeneca announced major job cuts and Eli Lilly & Co. reported a fourth quarter loss.

Drugmaker Astrazeneca reported today it had plans to cut 6,000 more jobs worldwide by 2013. Since the beginning of 2007 the company -- which has a total workforce of 67,000 -- has announced 15,000 layoffs to be made by 2013, AP reports.

Separately, Eli Lilly & Co. reported today a fourth quarter loss of $3.63 billion citing charges on its acquisition of ImClone Systems Inc. Since 2004, the company has cut more than 5,000 jobs.

Analysts say pharmaceutical companies are struggling as they invest great amounts of money in research to develop a drug but they find failures in late stages the drug’s development. This requires them to plan to reduce costs and make up for the losses.