Lucy Tobin: With endless remedies to choose from, what went wrong?

When AstraZeneca was wheeled into A&E a few years ago, bleeding revenues everywhere and its growth stunted by a lack of vitamins R&D, the professionals knew the prognosis was grim. They tried a bit of this and that: lowering medical costs by firing thousands of carers; buying some new body parts like the $15.6bn acquisition of MedImmune in 2007.

But nothing worked. And then, to stretch the analogy a little, just when they thought things couldn't get worse, the patient's head fell off. Or was cut off. No one will say.

Almost all of Astra's blockbuster medicines are now facing generic competition on the pharmacy shelves, or soon will. Three major pipeline hopes have failed in as many months. And there's only so long a company can hypnotise investors with cash hand-outs.

In that context, it's little wonder a German investor at the drug maker's AGM yesterday said he was "astounded" at Mr Brennan's "leav[ing] the ship on high seas". AstraZeneca's headhunters are going to have one hell of a job finding someone to take over.

In some ways, it's not such a different situation from when Mr Brennan replaced Sir Tom McKillop at the top of AstraZeneca in 2006. At the time, he joked with a colleague who had come to congratulate him: "Great job, shit timing." Could Mr Brennan have done more in his six years in charge? If instead of chucking almost $16bn at MedImmune he had made a play for Shire, the Dublin-headquartered drug maker that has made serious progress on its pipeline, Astra might not be in the state it's in today. Worse, though, was Mr Brennan's decision to cut back on research and development at the time when Astra needed it most.

It was that which put the drug maker into intensive care. Only time will tell if it pulls through.