We're back yet again, with our review of three of the most horrendous health-care stocks of the past week. Let's get right to it an review some of the big losers over the past few days.

Given up?
Shares of Israeli medical device maker Given Imaging (UNKNOWN:UNKNOWN) dropped nearly 12% this week. The steep fall came after a double-whammy of bad news.

Given announced on Tuesday that it's abandoning plans to sell to or merge with another company. The company said in October that it had attracted interest from several parties and was looking seriously at the potential for a deal. That deal ultimately didn't materialize.

The other bad news was that the largest holder of Given Imaging stock, Discount Investment Corporation, is looking to sell all of its 45.5% stake. DIC is a major investment firm in Israel and owns large positions in several Israeli firms, including the nation's largest cellular operator and largest grocery retail chain.

A noteworthy decline
(UNKNOWN:THRX.DL) shares sank more than 10% this week. The biopharmaceutical company announced on Wednesday that it plans to offer $250 million in convertible subordinated notes due in 2023.

One major reason Theravance cited for taking on more debt was to make potential milestone payments to its collaboration partner, GlaxoSmithKline (NYSE:GSK). Theravance and Glaxo recently submitted for a Marketing Authorization Approval in Europe for COPD drug Anoro and have also submitted to the FDA for approval for the drug in the United States.

Theravance also will probably use a portion of the new debt to pay off some old debt. The company has $172.5 million in convertible subordinated notes that mature at the beginning of 2015.  

The dilution solution
Aveo Pharmaceuticals
(NASDAQ:AVEO) shares tumbled 10% this week after announcing on Thursday that it intends to move forward with a $50 million secondary public offering.

The main factor for needing to generate more cash stems from the expected commercial launch of tivozanib later this year. The kidney cancer drug, developed by Aveo and partner Astellas Pharma, has an FDA decision date of July 28. 

Aveo's secondary offering of nearly 6.7 million shares represents about 15% of the company's total outstanding shares. The market seems to be pricing in a reasonable potential for FDA approval of tivozanib, since Aveo shares didn't fall as much as they could have with that amount of dilution.

Horrendously horrendous
What's the worst of the worst this week aside from the percentage drop for each stock? I'd have to say that Given Imaging gets the nod. Theravance and Aveo fell for temporary reasons that directly relate to long-term positives. Given, on the other hand, had its biggest owner say shalom (for goodbye, not hello) and saw prospects for a merger or buyout fall through. That qualifies for a horrendous week and potentially horrendous days ahead for the stock.

Keith Speights and The Motley Fool have no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.