AstraZeneca plunges by 7% as its patents run out

The withdrawal symptoms of an emptying drugs cabinet hit AstraZeneca today. Patent expiries meant its pre-tax profit dropped 7% to $3.3 billion (£2 billion) in the first quarter.

The numbers would have been even worse but for Astra's $500 million boost after a tax settlement with UK and US authorities.

The Big Pharma firm suffered lower sales, down 3% to $8.3 billion, as breast cancer drug Arimidex, asthma treatment Pulmicort and heart medicine Toprol XL fell out of patent and faced generic competition.

Now Astra's ailments look set to worsen as Nexium, its $5 billion-a-year blockbuster, comes out of patent in 2014 and Seroquel, its best-selling bipolar drug, faces generic competition next year.

"The slightly weaker sales concern us," said Dominic Valder, analyst at Evolution Securities.

"AstraZeneca has the largest patent cliff in the sector."

Astra has high hopes for its new heart drug Brilinta to replace lost revenues.