As evidenced by Pfizer's proposed $100 billion-plus takeover of AstraZeneca, Big Pharma is in the throes of the greatest period of consolidation in a decade. One reality remains unchanged, however: Drug prices keep defying the law of gravity. Since October 2007 the cost of brand-name medicines has soared, with prices doubling for dozens of established drugs that target everything from multiple sclerosis to cancer, blood pressure, and even erectile dysfunction, according to an analysis conducted for Bloomberg. While the consumer price index rose just 12% during the period, one diabetes drug quadrupled in price and another rose 160%, according to an analysis by DRX, a provider of comparison and management software for health plans. The recent series of acquisitions may push prices even higher, says Robert Kemp, an economist at the University of Louisiana at Monroe.