Acquisition mania in the pharmaceutical sector remains red-hot. Yesterday, King Pharmaceuticals (NYSE:KG) announced that it had increased its offer to acquire Alpharma (NYSE:ALO), and it was now taking that bid directly to the shareholders.

In late August, King revealed that it had made a $33 per share ($1.4 billion) bid for Alpharma. The latter company's board of directors immediately rejected the offer as too low. King didn't wait long to react, increasing its bid more than 12% to $37 per share. After Alpharma also rejected the new offer, King announced a tender offer to bypass the board and reach out to shareholders.

Why all this effort? The past 18 months have been rough on King. Hypertension treatment Altace has begun to face generic competition, and muscle relaxant Skelaxin will face generic competition sooner than expected. The company's predicament will only get tougher, as competition against King's thrombin agent and other top drugs ramps up. Rival drugmakers like Omrix Biopharmaceuticals (NASDAQ:OMRI) and ZymoGenetics (NASDAQ:ZGEN) are hot on King's heels here.

For King, getting Alpharma would make it the leader in the new abuse-deterrent class of opioid pain medications, and give it other pain drug compounds, such as Alpharma's exciting Flector patch.

However, there is a lot of risk in this strategy. If insurers are unwilling to pay for abuse-deterrent drugs, or if the FDA doesn't approve these compounds for marketing later this year, King and its partner Pain Therapeutics' (NASDAQ:PTIE) attempted foray into this class of therapies could become an expensive bust.

Hostile takeovers are never easy for the acquirer, and that's true, here, too. Alpharma's share price currently trades above King's $37-per-share proposed tender offer, which suggests that shareholders might think a better deal from King or one of its rivals is forthcoming. With the tender offer set to expire Oct. 10, investors eager to see what happens next won't have long to wait.