With the kids (drugs) all grown up and the eldest about to go away to college (off patent), it looks like Abbott Laboratories (NYSE: ABT) and Takeda are ending their marriage of more than 30 years.

Revenue in the companies' joint venture, TAP Pharmaceutical Products, topped more than $3 billion last year from its two currently marketed products.

In the divorce, Abbott gets the rights to prostate cancer treatment Lupron, while Takeda will get the rights to heartburn drug Prevacid. Abbott will also get cash and royalties on products, since Prevacid has much higher sales than Lupron.

Prevacid's patent is set to expire late next year, which will obviously have drastic effects on sales in 2010 and beyond. The drug's sales might already be hurt by generics this year, since rival Wyeth's (NYSE: WYE) Protonix is now available as a generic from Teva Pharmaceutical (Nasdaq: TEVA) and as a licensed generic from Wyeth.

The duo has developed a successor to Prevacid, named tak390mr, which is currently under review at the FDA. Only time will tell whether Takeda can persuade patients to switch to Prevacid, especially after the drug becomes available as a generic.

The breakup seems like a good move for both companies. In the short term, the 50/50 split shouldn't affect the companies' financials. In the long term, the companies might be able to save money by not having the additional overhead of a joint venture. While Abbott gives up some control of its income stream from Prevacid and potentially other products that were in development by TAP, it has enough on its plate with anti-inflammatory Humira and hopefully a new drug-eluting stent, that it shouldn't miss its former partner that much.

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Fool contributor Brian Orelli, Ph.D., doesn't own shares of any company mentioned in this article. The Fool's disclosure policy prefers makeups to breakups.