The drugmaker has sold $6.9 billion in bonds, which makes the sale the largest US debt offering in more than five years. And, of course, AstraZeneca will use the proceeds to repay commercial paper that financed its $15.2 billion acquisition of MedImmune earlier this summer. The offering ranks as the biggest since March 2002, when General Electric sold $11 billion of fixed- and floating-rate debt.

Investors snapped up the bonds in part because drugmakers have been relatively untouched by losses on subprime home loans that have extended to banks and mortgage lenders. “There’s still cash out there for investment-grade offerings,” Sabur Moini, a portfolio manager at Payden & Rygel, tells Bloomberg News. “It helps that it’s not a bank or financial institution but a pharmaceutical company selling bonds.”

But this comes at a price. The drugmaker issued four new tranches of paper - $2.75 billion worth of 30-year notes at 6.45 per cent; $1.75 billion in 10-year notes at 5.9 per cent; $1.75 billion of 5-year notes at 5.4 per cent, and then $650 million in two-year floating rates notes at 30 basis points over $3 million LIBOR, or London Interbank Bid Rate.

As The Financial Times’ Alphaville points out, this compares with a reported weighted average of 5.4 per cent attached to the drugmaker’s previous $13 billion commercial paper program. In a statement, AstraZeneca ceo Dave Brennan says he’s delighted at the sale.

“Clearly, companies have to pay for the comfort and security of long-term money,” Alphaville writes. “In private we guess he would have used the word ‘relieved.’ ”